
Préférences
Moteurs de recherche


JavaTM 2 Platform Std. Ed. v1.6.0
java.util

Method Summary  

static

asList(T... a)
Returns a fixedsize list backed by the specified array. 

static int 
binarySearch(byte[] a,
byte key)
Searches the specified array of bytes for the specified value using the binary search algorithm. 

static int 
binarySearch(byte[] a,
int fromIndex,
int toIndex,
byte key)
Searches a range of the specified array of bytes for the specified value using the binary search algorithm. 

static int 
binarySearch(char[] a,
char key)
Searches the specified array of chars for the specified value using the binary search algorithm. 

static int 
binarySearch(char[] a,
int fromIndex,
int toIndex,
char key)
Searches a range of the specified array of chars for the specified value using the binary search algorithm. 

static int 
binarySearch(double[] a,
double key)
Searches the specified array of doubles for the specified value using the binary search algorithm. 

static int 
binarySearch(double[] a,
int fromIndex,
int toIndex,
double key)
Searches a range of the specified array of doubles for the specified value using the binary search algorithm. 

static int 
binarySearch(float[] a,
float key)
Searches the specified array of floats for the specified value using the binary search algorithm. 

static int 
binarySearch(float[] a,
int fromIndex,
int toIndex,
float key)
Searches a range of the specified array of floats for the specified value using the binary search algorithm. 

static int 
binarySearch(int[] a,
int key)
Searches the specified array of ints for the specified value using the binary search algorithm. 

static int 
binarySearch(int[] a,
int fromIndex,
int toIndex,
int key)
Searches a range of the specified array of ints for the specified value using the binary search algorithm. 

static int 
binarySearch(long[] a,
int fromIndex,
int toIndex,
long key)
Searches a range of the specified array of longs for the specified value using the binary search algorithm. 

static int 
binarySearch(long[] a,
long key)
Searches the specified array of longs for the specified value using the binary search algorithm. 

static int 
binarySearch(Object[] a,
int fromIndex,
int toIndex,
Object key)
Searches a range of the specified array for the specified object using the binary search algorithm. 

static int 
binarySearch(Object[] a,
Object key)
Searches the specified array for the specified object using the binary search algorithm. 

static int 
binarySearch(short[] a,
int fromIndex,
int toIndex,
short key)
Searches a range of the specified array of shorts for the specified value using the binary search algorithm. 

static int 
binarySearch(short[] a,
short key)
Searches the specified array of shorts for the specified value using the binary search algorithm. 

static

binarySearch(T[] a,
int fromIndex,
int toIndex,
T key,
Comparator<? super T> c)
Searches a range of the specified array for the specified object using the binary search algorithm. 

static

binarySearch(T[] a,
T key,
Comparator<? super T> c)
Searches the specified array for the specified object using the binary search algorithm. 

static boolean[] 
copyOf(boolean[] original,
int newLength)
Copies the specified array, truncating or padding with false (if necessary) so the copy has the specified length. 

static byte[] 
copyOf(byte[] original,
int newLength)
Copies the specified array, truncating or padding with zeros (if necessary) so the copy has the specified length. 

static char[] 
copyOf(char[] original,
int newLength)
Copies the specified array, truncating or padding with null characters (if necessary) so the copy has the specified length. 

static double[] 
copyOf(double[] original,
int newLength)
Copies the specified array, truncating or padding with zeros (if necessary) so the copy has the specified length. 

static float[] 
copyOf(float[] original,
int newLength)
Copies the specified array, truncating or padding with zeros (if necessary) so the copy has the specified length. 

static int[] 
copyOf(int[] original,
int newLength)
Copies the specified array, truncating or padding with zeros (if necessary) so the copy has the specified length. 

static long[] 
copyOf(long[] original,
int newLength)
Copies the specified array, truncating or padding with zeros (if necessary) so the copy has the specified length. 

static short[] 
copyOf(short[] original,
int newLength)
Copies the specified array, truncating or padding with zeros (if necessary) so the copy has the specified length. 

static

copyOf(T[] original,
int newLength)
Copies the specified array, truncating or padding with nulls (if necessary) so the copy has the specified length. 

static

copyOf(U[] original,
int newLength,
Class<? extends T[]> newType)
Copies the specified array, truncating or padding with nulls (if necessary) so the copy has the specified length. 

static boolean[] 
copyOfRange(boolean[] original,
int from,
int to)
Copies the specified range of the specified array into a new array. 

static byte[] 
copyOfRange(byte[] original,
int from,
int to)
Copies the specified range of the specified array into a new array. 

static char[] 
copyOfRange(char[] original,
int from,
int to)
Copies the specified range of the specified array into a new array. 

static double[] 
copyOfRange(double[] original,
int from,
int to)
Copies the specified range of the specified array into a new array. 

static float[] 
copyOfRange(float[] original,
int from,
int to)
Copies the specified range of the specified array into a new array. 

static int[] 
copyOfRange(int[] original,
int from,
int to)
Copies the specified range of the specified array into a new array. 

static long[] 
copyOfRange(long[] original,
int from,
int to)
Copies the specified range of the specified array into a new array. 

static short[] 
copyOfRange(short[] original,
int from,
int to)
Copies the specified range of the specified array into a new array. 

static

copyOfRange(T[] original,
int from,
int to)
Copies the specified range of the specified array into a new array. 

static

copyOfRange(U[] original,
int from,
int to,
Class<? extends T[]> newType)
Copies the specified range of the specified array into a new array. 

static boolean 
deepEquals(Object[] a1,
Object[] a2)
Returns true if the two specified arrays are deeply equal to one another. 

static int 
deepHashCode(Object[] a)
Returns a hash code based on the "deep contents" of the specified array. 

static String 
deepToString(Object[] a)
Returns a string representation of the "deep contents" of the specified array. 

static boolean 
equals(boolean[] a,
boolean[] a2)
Returns true if the two specified arrays of booleans are equal to one another. 

static boolean 
equals(byte[] a,
byte[] a2)
Returns true if the two specified arrays of bytes are equal to one another. 

static boolean 
equals(char[] a,
char[] a2)
Returns true if the two specified arrays of chars are equal to one another. 

static boolean 
equals(double[] a,
double[] a2)
Returns true if the two specified arrays of doubles are equal to one another. 

static boolean 
equals(float[] a,
float[] a2)
Returns true if the two specified arrays of floats are equal to one another. 

static boolean 
equals(int[] a,
int[] a2)
Returns true if the two specified arrays of ints are equal to one another. 

static boolean 
equals(long[] a,
long[] a2)
Returns true if the two specified arrays of longs are equal to one another. 

static boolean 
equals(Object[] a,
Object[] a2)
Returns true if the two specified arrays of Objects are equal to one another. 

static boolean 
equals(short[] a,
short[] a2)
Returns true if the two specified arrays of shorts are equal to one another. 

static void 
fill(boolean[] a,
boolean val)
Assigns the specified boolean value to each element of the specified array of booleans. 

static void 
fill(boolean[] a,
int fromIndex,
int toIndex,
boolean val)
Assigns the specified boolean value to each element of the specified range of the specified array of booleans. 

static void 
fill(byte[] a,
byte val)
Assigns the specified byte value to each element of the specified array of bytes. 

static void 
fill(byte[] a,
int fromIndex,
int toIndex,
byte val)
Assigns the specified byte value to each element of the specified range of the specified array of bytes. 

static void 
fill(char[] a,
char val)
Assigns the specified char value to each element of the specified array of chars. 

static void 
fill(char[] a,
int fromIndex,
int toIndex,
char val)
Assigns the specified char value to each element of the specified range of the specified array of chars. 

static void 
fill(double[] a,
double val)
Assigns the specified double value to each element of the specified array of doubles. 

static void 
fill(double[] a,
int fromIndex,
int toIndex,
double val)
Assigns the specified double value to each element of the specified range of the specified array of doubles. 

static void 
fill(float[] a,
float val)
Assigns the specified float value to each element of the specified array of floats. 

static void 
fill(float[] a,
int fromIndex,
int toIndex,
float val)
Assigns the specified float value to each element of the specified range of the specified array of floats. 

static void 
fill(int[] a,
int val)
Assigns the specified int value to each element of the specified array of ints. 

static void 
fill(int[] a,
int fromIndex,
int toIndex,
int val)
Assigns the specified int value to each element of the specified range of the specified array of ints. 

static void 
fill(long[] a,
int fromIndex,
int toIndex,
long val)
Assigns the specified long value to each element of the specified range of the specified array of longs. 

static void 
fill(long[] a,
long val)
Assigns the specified long value to each element of the specified array of longs. 

static void 
fill(Object[] a,
int fromIndex,
int toIndex,
Object val)
Assigns the specified Object reference to each element of the specified range of the specified array of Objects. 

static void 
fill(Object[] a,
Object val)
Assigns the specified Object reference to each element of the specified array of Objects. 

static void 
fill(short[] a,
int fromIndex,
int toIndex,
short val)
Assigns the specified short value to each element of the specified range of the specified array of shorts. 

static void 
fill(short[] a,
short val)
Assigns the specified short value to each element of the specified array of shorts. 

static int 
hashCode(boolean[] a)
Returns a hash code based on the contents of the specified array. 

static int 
hashCode(byte[] a)
Returns a hash code based on the contents of the specified array. 

static int 
hashCode(char[] a)
Returns a hash code based on the contents of the specified array. 

static int 
hashCode(double[] a)
Returns a hash code based on the contents of the specified array. 

static int 
hashCode(float[] a)
Returns a hash code based on the contents of the specified array. 

static int 
hashCode(int[] a)
Returns a hash code based on the contents of the specified array. 

static int 
hashCode(long[] a)
Returns a hash code based on the contents of the specified array. 

static int 
hashCode(Object[] a)
Returns a hash code based on the contents of the specified array. 

static int 
hashCode(short[] a)
Returns a hash code based on the contents of the specified array. 

static void 
sort(byte[] a)
Sorts the specified array of bytes into ascending numerical order. 

static void 
sort(byte[] a,
int fromIndex,
int toIndex)
Sorts the specified range of the specified array of bytes into ascending numerical order. 

static void 
sort(char[] a)
Sorts the specified array of chars into ascending numerical order. 

static void 
sort(char[] a,
int fromIndex,
int toIndex)
Sorts the specified range of the specified array of chars into ascending numerical order. 

static void 
sort(double[] a)
Sorts the specified array of doubles into ascending numerical order. 

static void 
sort(double[] a,
int fromIndex,
int toIndex)
Sorts the specified range of the specified array of doubles into ascending numerical order. 

static void 
sort(float[] a)
Sorts the specified array of floats into ascending numerical order. 

static void 
sort(float[] a,
int fromIndex,
int toIndex)
Sorts the specified range of the specified array of floats into ascending numerical order. 

static void 
sort(int[] a)
Sorts the specified array of ints into ascending numerical order. 

static void 
sort(int[] a,
int fromIndex,
int toIndex)
Sorts the specified range of the specified array of ints into ascending numerical order. 

static void 
sort(long[] a)
Sorts the specified array of longs into ascending numerical order. 

static void 
sort(long[] a,
int fromIndex,
int toIndex)
Sorts the specified range of the specified array of longs into ascending numerical order. 

static void 
sort(Object[] a)
Sorts the specified array of objects into ascending order, according to the natural ordering of its elements. 

static void 
sort(Object[] a,
int fromIndex,
int toIndex)
Sorts the specified range of the specified array of objects into ascending order, according to the natural ordering of its elements. 

static void 
sort(short[] a)
Sorts the specified array of shorts into ascending numerical order. 

static void 
sort(short[] a,
int fromIndex,
int toIndex)
Sorts the specified range of the specified array of shorts into ascending numerical order. 

static

sort(T[] a,
Comparator<? super T> c)
Sorts the specified array of objects according to the order induced by the specified comparator. 

static

sort(T[] a,
int fromIndex,
int toIndex,
Comparator<? super T> c)
Sorts the specified range of the specified array of objects according to the order induced by the specified comparator. 

static String 
toString(boolean[] a)
Returns a string representation of the contents of the specified array. 

static String 
toString(byte[] a)
Returns a string representation of the contents of the specified array. 

static String 
toString(char[] a)
Returns a string representation of the contents of the specified array. 

static String 
toString(double[] a)
Returns a string representation of the contents of the specified array. 

static String 
toString(float[] a)
Returns a string representation of the contents of the specified array. 

static String 
toString(int[] a)
Returns a string representation of the contents of the specified array. 

static String 
toString(long[] a)
Returns a string representation of the contents of the specified array. 

static String 
toString(Object[] a)
Returns a string representation of the contents of the specified array. 

static String 
toString(short[] a)
Returns a string representation of the contents of the specified array. 
Methods inherited from class java.lang.Object 

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait 
Method Detail 

public static void sort(long[] a)
a
 the array to be sortedpublic static void sort(long[] a, int fromIndex, int toIndex)
The sorting algorithm is a tuned quicksort, adapted from Jon L. Bentley and M. Douglas McIlroy's "Engineering a Sort Function", SoftwarePractice and Experience, Vol. 23(11) P. 12491265 (November 1993). This algorithm offers n*log(n) performance on many data sets that cause other quicksorts to degrade to quadratic performance.
a
 the array to be sortedfromIndex
 the index of the first element (inclusive) to be
sortedtoIndex
 the index of the last element (exclusive) to be sorted
IllegalArgumentException
 if fromIndex > toIndex
ArrayIndexOutOfBoundsException
 if fromIndex < 0 or
toIndex > a.lengthpublic static void sort(int[] a)
a
 the array to be sortedpublic static void sort(int[] a, int fromIndex, int toIndex)
The sorting algorithm is a tuned quicksort, adapted from Jon L. Bentley and M. Douglas McIlroy's "Engineering a Sort Function", SoftwarePractice and Experience, Vol. 23(11) P. 12491265 (November 1993). This algorithm offers n*log(n) performance on many data sets that cause other quicksorts to degrade to quadratic performance.
a
 the array to be sortedfromIndex
 the index of the first element (inclusive) to be
sortedtoIndex
 the index of the last element (exclusive) to be sorted
IllegalArgumentException
 if fromIndex > toIndex
ArrayIndexOutOfBoundsException
 if fromIndex < 0 or
toIndex > a.lengthpublic static void sort(short[] a)
a
 the array to be sortedpublic static void sort(short[] a, int fromIndex, int toIndex)
The sorting algorithm is a tuned quicksort, adapted from Jon L. Bentley and M. Douglas McIlroy's "Engineering a Sort Function", SoftwarePractice and Experience, Vol. 23(11) P. 12491265 (November 1993). This algorithm offers n*log(n) performance on many data sets that cause other quicksorts to degrade to quadratic performance.
a
 the array to be sortedfromIndex
 the index of the first element (inclusive) to be
sortedtoIndex
 the index of the last element (exclusive) to be sorted
IllegalArgumentException
 if fromIndex > toIndex
ArrayIndexOutOfBoundsException
 if fromIndex < 0 or
toIndex > a.lengthpublic static void sort(char[] a)
a
 the array to be sortedpublic static void sort(char[] a, int fromIndex, int toIndex)
The sorting algorithm is a tuned quicksort, adapted from Jon L. Bentley and M. Douglas McIlroy's "Engineering a Sort Function", SoftwarePractice and Experience, Vol. 23(11) P. 12491265 (November 1993). This algorithm offers n*log(n) performance on many data sets that cause other quicksorts to degrade to quadratic performance.
a
 the array to be sortedfromIndex
 the index of the first element (inclusive) to be
sortedtoIndex
 the index of the last element (exclusive) to be sorted
IllegalArgumentException
 if fromIndex > toIndex
ArrayIndexOutOfBoundsException
 if fromIndex < 0 or
toIndex > a.lengthpublic static void sort(byte[] a)
a
 the array to be sortedpublic static void sort(byte[] a, int fromIndex, int toIndex)
The sorting algorithm is a tuned quicksort, adapted from Jon L. Bentley and M. Douglas McIlroy's "Engineering a Sort Function", SoftwarePractice and Experience, Vol. 23(11) P. 12491265 (November 1993). This algorithm offers n*log(n) performance on many data sets that cause other quicksorts to degrade to quadratic performance.
a
 the array to be sortedfromIndex
 the index of the first element (inclusive) to be
sortedtoIndex
 the index of the last element (exclusive) to be sorted
IllegalArgumentException
 if fromIndex > toIndex
ArrayIndexOutOfBoundsException
 if fromIndex < 0 or
toIndex > a.lengthpublic static void sort(double[] a)
The <
relation does not provide a total order on
all floatingpoint values; although they are distinct numbers
0.0 == 0.0
is true
and a NaN value
compares neither less than, greater than, nor equal to any
floatingpoint value, even itself. To allow the sort to
proceed, instead of using the <
relation to
determine ascending numerical order, this method uses the total
order imposed by Double.compareTo(java.lang.Double)
. This ordering
differs from the <
relation in that
0.0
is treated as less than 0.0
and
NaN is considered greater than any other floatingpoint value.
For the purposes of sorting, all NaN values are considered
equivalent and equal.
The sorting algorithm is a tuned quicksort, adapted from Jon L. Bentley and M. Douglas McIlroy's "Engineering a Sort Function", SoftwarePractice and Experience, Vol. 23(11) P. 12491265 (November 1993). This algorithm offers n*log(n) performance on many data sets that cause other quicksorts to degrade to quadratic performance.
a
 the array to be sortedpublic static void sort(double[] a, int fromIndex, int toIndex)
The <
relation does not provide a total order on
all floatingpoint values; although they are distinct numbers
0.0 == 0.0
is true
and a NaN value
compares neither less than, greater than, nor equal to any
floatingpoint value, even itself. To allow the sort to
proceed, instead of using the <
relation to
determine ascending numerical order, this method uses the total
order imposed by Double.compareTo(java.lang.Double)
. This ordering
differs from the <
relation in that
0.0
is treated as less than 0.0
and
NaN is considered greater than any other floatingpoint value.
For the purposes of sorting, all NaN values are considered
equivalent and equal.
The sorting algorithm is a tuned quicksort, adapted from Jon L. Bentley and M. Douglas McIlroy's "Engineering a Sort Function", SoftwarePractice and Experience, Vol. 23(11) P. 12491265 (November 1993). This algorithm offers n*log(n) performance on many data sets that cause other quicksorts to degrade to quadratic performance.
a
 the array to be sortedfromIndex
 the index of the first element (inclusive) to be
sortedtoIndex
 the index of the last element (exclusive) to be sorted
IllegalArgumentException
 if fromIndex > toIndex
ArrayIndexOutOfBoundsException
 if fromIndex < 0 or
toIndex > a.lengthpublic static void sort(float[] a)
The <
relation does not provide a total order on
all floatingpoint values; although they are distinct numbers
0.0f == 0.0f
is true
and a NaN value
compares neither less than, greater than, nor equal to any
floatingpoint value, even itself. To allow the sort to
proceed, instead of using the <
relation to
determine ascending numerical order, this method uses the total
order imposed by Float.compareTo(java.lang.Float)
. This ordering
differs from the <
relation in that
0.0f
is treated as less than 0.0f
and
NaN is considered greater than any other floatingpoint value.
For the purposes of sorting, all NaN values are considered
equivalent and equal.
The sorting algorithm is a tuned quicksort, adapted from Jon L. Bentley and M. Douglas McIlroy's "Engineering a Sort Function", SoftwarePractice and Experience, Vol. 23(11) P. 12491265 (November 1993). This algorithm offers n*log(n) performance on many data sets that cause other quicksorts to degrade to quadratic performance.
a
 the array to be sortedpublic static void sort(float[] a, int fromIndex, int toIndex)
The <
relation does not provide a total order on
all floatingpoint values; although they are distinct numbers
0.0f == 0.0f
is true
and a NaN value
compares neither less than, greater than, nor equal to any
floatingpoint value, even itself. To allow the sort to
proceed, instead of using the <
relation to
determine ascending numerical order, this method uses the total
order imposed by Float.compareTo(java.lang.Float)
. This ordering
differs from the <
relation in that
0.0f
is treated as less than 0.0f
and
NaN is considered greater than any other floatingpoint value.
For the purposes of sorting, all NaN values are considered
equivalent and equal.
The sorting algorithm is a tuned quicksort, adapted from Jon L. Bentley and M. Douglas McIlroy's "Engineering a Sort Function", SoftwarePractice and Experience, Vol. 23(11) P. 12491265 (November 1993). This algorithm offers n*log(n) performance on many data sets that cause other quicksorts to degrade to quadratic performance.
a
 the array to be sortedfromIndex
 the index of the first element (inclusive) to be
sortedtoIndex
 the index of the last element (exclusive) to be sorted
IllegalArgumentException
 if fromIndex > toIndex
ArrayIndexOutOfBoundsException
 if fromIndex < 0 or
toIndex > a.lengthpublic static void sort(Object[] a)
Comparable
interface. Furthermore, all
elements in the array must be mutually comparable (that is,
e1.compareTo(e2) must not throw a ClassCastException
for any elements e1 and e2 in the array).This sort is guaranteed to be stable: equal elements will not be reordered as a result of the sort.
The sorting algorithm is a modified mergesort (in which the merge is omitted if the highest element in the low sublist is less than the lowest element in the high sublist). This algorithm offers guaranteed n*log(n) performance.
a
 the array to be sorted
ClassCastException
 if the array contains elements that are not
mutually comparable (for example, strings and integers).public static void sort(Object[] a, int fromIndex, int toIndex)
Comparable
interface. Furthermore, all elements in this range must be mutually
comparable (that is, e1.compareTo(e2) must not throw a
ClassCastException for any elements e1 and
e2 in the array).This sort is guaranteed to be stable: equal elements will not be reordered as a result of the sort.
The sorting algorithm is a modified mergesort (in which the merge is omitted if the highest element in the low sublist is less than the lowest element in the high sublist). This algorithm offers guaranteed n*log(n) performance.
a
 the array to be sortedfromIndex
 the index of the first element (inclusive) to be
sortedtoIndex
 the index of the last element (exclusive) to be sorted
IllegalArgumentException
 if fromIndex > toIndex
ArrayIndexOutOfBoundsException
 if fromIndex < 0 or
toIndex > a.length
ClassCastException
 if the array contains elements that are
not mutually comparable (for example, strings and
integers).public static <T> void sort(T[] a, Comparator<? super T> c)
This sort is guaranteed to be stable: equal elements will not be reordered as a result of the sort.
The sorting algorithm is a modified mergesort (in which the merge is omitted if the highest element in the low sublist is less than the lowest element in the high sublist). This algorithm offers guaranteed n*log(n) performance.
a
 the array to be sortedc
 the comparator to determine the order of the array. A
null value indicates that the elements'
natural ordering should be used.
ClassCastException
 if the array contains elements that are
not mutually comparable using the specified comparator.public static <T> void sort(T[] a, int fromIndex, int toIndex, Comparator<? super T> c)
This sort is guaranteed to be stable: equal elements will not be reordered as a result of the sort.
The sorting algorithm is a modified mergesort (in which the merge is omitted if the highest element in the low sublist is less than the lowest element in the high sublist). This algorithm offers guaranteed n*log(n) performance.
a
 the array to be sortedfromIndex
 the index of the first element (inclusive) to be
sortedtoIndex
 the index of the last element (exclusive) to be sortedc
 the comparator to determine the order of the array. A
null value indicates that the elements'
natural ordering should be used.
ClassCastException
 if the array contains elements that are not
mutually comparable using the specified comparator.
IllegalArgumentException
 if fromIndex > toIndex
ArrayIndexOutOfBoundsException
 if fromIndex < 0 or
toIndex > a.lengthpublic static int binarySearch(long[] a, long key)
sort(long[])
method) prior to making this call. If it
is not sorted, the results are undefined. If the array contains
multiple elements with the specified value, there is no guarantee which
one will be found.
a
 the array to be searchedkey
 the value to be searched for
public static int binarySearch(long[] a, int fromIndex, int toIndex, long key)
sort(long[], int, int)
method)
prior to making this call. If it
is not sorted, the results are undefined. If the range contains
multiple elements with the specified value, there is no guarantee which
one will be found.
a
 the array to be searchedfromIndex
 the index of the first element (inclusive) to be
searchedtoIndex
 the index of the last element (exclusive) to be searchedkey
 the value to be searched for
IllegalArgumentException
 if fromIndex > toIndex
ArrayIndexOutOfBoundsException
 if fromIndex < 0 or toIndex > a.length
public static int binarySearch(int[] a, int key)
sort(int[])
method) prior to making this call. If it
is not sorted, the results are undefined. If the array contains
multiple elements with the specified value, there is no guarantee which
one will be found.
a
 the array to be searchedkey
 the value to be searched for
public static int binarySearch(int[] a, int fromIndex, int toIndex, int key)
sort(int[], int, int)
method)
prior to making this call. If it
is not sorted, the results are undefined. If the range contains
multiple elements with the specified value, there is no guarantee which
one will be found.
a
 the array to be searchedfromIndex
 the index of the first element (inclusive) to be
searchedtoIndex
 the index of the last element (exclusive) to be searchedkey
 the value to be searched for
IllegalArgumentException
 if fromIndex > toIndex
ArrayIndexOutOfBoundsException
 if fromIndex < 0 or toIndex > a.length
public static int binarySearch(short[] a, short key)
sort(short[])
method) prior to making this call. If
it is not sorted, the results are undefined. If the array contains
multiple elements with the specified value, there is no guarantee which
one will be found.
a
 the array to be searchedkey
 the value to be searched for
public static int binarySearch(short[] a, int fromIndex, int toIndex, short key)
sort(short[], int, int)
method)
prior to making this call. If
it is not sorted, the results are undefined. If the range contains
multiple elements with the specified value, there is no guarantee which
one will be found.
a
 the array to be searchedfromIndex
 the index of the first element (inclusive) to be
searchedtoIndex
 the index of the last element (exclusive) to be searchedkey
 the value to be searched for
IllegalArgumentException
 if fromIndex > toIndex
ArrayIndexOutOfBoundsException
 if fromIndex < 0 or toIndex > a.length
public static int binarySearch(char[] a, char key)
sort(char[])
method) prior to making this call. If it
is not sorted, the results are undefined. If the array contains
multiple elements with the specified value, there is no guarantee which
one will be found.
a
 the array to be searchedkey
 the value to be searched for
public static int binarySearch(char[] a, int fromIndex, int toIndex, char key)
sort(char[], int, int)
method)
prior to making this call. If it
is not sorted, the results are undefined. If the range contains
multiple elements with the specified value, there is no guarantee which
one will be found.
a
 the array to be searchedfromIndex
 the index of the first element (inclusive) to be
searchedtoIndex
 the index of the last element (exclusive) to be searchedkey
 the value to be searched for
IllegalArgumentException
 if fromIndex > toIndex
ArrayIndexOutOfBoundsException
 if fromIndex < 0 or toIndex > a.length
public static int binarySearch(byte[] a, byte key)
sort(byte[])
method) prior to making this call. If it
is not sorted, the results are undefined. If the array contains
multiple elements with the specified value, there is no guarantee which
one will be found.
a
 the array to be searchedkey
 the value to be searched for
public static int binarySearch(byte[] a, int fromIndex, int toIndex, byte key)
sort(byte[], int, int)
method)
prior to making this call. If it
is not sorted, the results are undefined. If the range contains
multiple elements with the specified value, there is no guarantee which
one will be found.
a
 the array to be searchedfromIndex
 the index of the first element (inclusive) to be
searchedtoIndex
 the index of the last element (exclusive) to be searchedkey
 the value to be searched for
IllegalArgumentException
 if fromIndex > toIndex
ArrayIndexOutOfBoundsException
 if fromIndex < 0 or toIndex > a.length
public static int binarySearch(double[] a, double key)
sort(double[])
method) prior to making this call.
If it is not sorted, the results are undefined. If the array contains
multiple elements with the specified value, there is no guarantee which
one will be found. This method considers all NaN values to be
equivalent and equal.
a
 the array to be searchedkey
 the value to be searched for
public static int binarySearch(double[] a, int fromIndex, int toIndex, double key)
sort(double[], int, int)
method)
prior to making this call.
If it is not sorted, the results are undefined. If the range contains
multiple elements with the specified value, there is no guarantee which
one will be found. This method considers all NaN values to be
equivalent and equal.
a
 the array to be searchedfromIndex
 the index of the first element (inclusive) to be
searchedtoIndex
 the index of the last element (exclusive) to be searchedkey
 the value to be searched for
IllegalArgumentException
 if fromIndex > toIndex
ArrayIndexOutOfBoundsException
 if fromIndex < 0 or toIndex > a.length
public static int binarySearch(float[] a, float key)
sort(float[])
method) prior to making this call. If
it is not sorted, the results are undefined. If the array contains
multiple elements with the specified value, there is no guarantee which
one will be found. This method considers all NaN values to be
equivalent and equal.
a
 the array to be searchedkey
 the value to be searched for
public static int binarySearch(float[] a, int fromIndex, int toIndex, float key)
sort(float[], int, int)
method)
prior to making this call. If
it is not sorted, the results are undefined. If the range contains
multiple elements with the specified value, there is no guarantee which
one will be found. This method considers all NaN values to be
equivalent and equal.
a
 the array to be searchedfromIndex
 the index of the first element (inclusive) to be
searchedtoIndex
 the index of the last element (exclusive) to be searchedkey
 the value to be searched for
IllegalArgumentException
 if fromIndex > toIndex
ArrayIndexOutOfBoundsException
 if fromIndex < 0 or toIndex > a.length
public static int binarySearch(Object[] a, Object key)
sort(Object[])
method) prior to making this call.
If it is not sorted, the results are undefined.
(If the array contains elements that are not mutually comparable (for
example, strings and integers), it cannot be sorted according
to the natural ordering of its elements, hence results are undefined.)
If the array contains multiple
elements equal to the specified object, there is no guarantee which
one will be found.
a
 the array to be searchedkey
 the value to be searched for
ClassCastException
 if the search key is not comparable to the
elements of the array.public static int binarySearch(Object[] a, int fromIndex, int toIndex, Object key)
sort(Object[], int, int)
method) prior to making this
call. If it is not sorted, the results are undefined.
(If the range contains elements that are not mutually comparable (for
example, strings and integers), it cannot be sorted according
to the natural ordering of its elements, hence results are undefined.)
If the range contains multiple
elements equal to the specified object, there is no guarantee which
one will be found.
a
 the array to be searchedfromIndex
 the index of the first element (inclusive) to be
searchedtoIndex
 the index of the last element (exclusive) to be searchedkey
 the value to be searched for
ClassCastException
 if the search key is not comparable to the
elements of the array within the specified range.
IllegalArgumentException
 if fromIndex > toIndex
ArrayIndexOutOfBoundsException
 if fromIndex < 0 or toIndex > a.length
public static <T> int binarySearch(T[] a, T key, Comparator<? super T> c)
sort(T[], Comparator)
method) prior to making this call. If it is
not sorted, the results are undefined.
If the array contains multiple
elements equal to the specified object, there is no guarantee which one
will be found.
a
 the array to be searchedkey
 the value to be searched forc
 the comparator by which the array is ordered. A
null value indicates that the elements'
natural ordering should be used.
ClassCastException
 if the array contains elements that are not
mutually comparable using the specified comparator,
or the search key is not comparable to the
elements of the array using this comparator.public static <T> int binarySearch(T[] a, int fromIndex, int toIndex, T key, Comparator<? super T> c)
sort(T[], int, int, Comparator)
method) prior to making this call.
If it is not sorted, the results are undefined.
If the range contains multiple elements equal to the specified object,
there is no guarantee which one will be found.
a
 the array to be searchedfromIndex
 the index of the first element (inclusive) to be
searchedtoIndex
 the index of the last element (exclusive) to be searchedkey
 the value to be searched forc
 the comparator by which the array is ordered. A
null value indicates that the elements'
natural ordering should be used.
ClassCastException
 if the range contains elements that are not
mutually comparable using the specified comparator,
or the search key is not comparable to the
elements in the range using this comparator.
IllegalArgumentException
 if fromIndex > toIndex
ArrayIndexOutOfBoundsException
 if fromIndex < 0 or toIndex > a.length
public static boolean equals(long[] a, long[] a2)
a
 one array to be tested for equalitya2
 the other array to be tested for equality
public static boolean equals(int[] a, int[] a2)
a
 one array to be tested for equalitya2
 the other array to be tested for equality
public static boolean equals(short[] a, short[] a2)
a
 one array to be tested for equalitya2
 the other array to be tested for equality
public static boolean equals(char[] a, char[] a2)
a
 one array to be tested for equalitya2
 the other array to be tested for equality
public static boolean equals(byte[] a, byte[] a2)
a
 one array to be tested for equalitya2
 the other array to be tested for equality
public static boolean equals(boolean[] a, boolean[] a2)
a
 one array to be tested for equalitya2
 the other array to be tested for equality
public static boolean equals(double[] a, double[] a2)
Two doubles d1 and d2 are considered equal if:
new Double(d1).equals(new Double(d2))(Unlike the == operator, this method considers NaN equals to itself, and 0.0d unequal to 0.0d.)
a
 one array to be tested for equalitya2
 the other array to be tested for equality
Double.equals(Object)
public static boolean equals(float[] a, float[] a2)
Two floats f1 and f2 are considered equal if:
new Float(f1).equals(new Float(f2))(Unlike the == operator, this method considers NaN equals to itself, and 0.0f unequal to 0.0f.)
a
 one array to be tested for equalitya2
 the other array to be tested for equality
Float.equals(Object)
public static boolean equals(Object[] a, Object[] a2)
a
 one array to be tested for equalitya2
 the other array to be tested for equality
public static void fill(long[] a, long val)
a
 the array to be filledval
 the value to be stored in all elements of the arraypublic static void fill(long[] a, int fromIndex, int toIndex, long val)
a
 the array to be filledfromIndex
 the index of the first element (inclusive) to be
filled with the specified valuetoIndex
 the index of the last element (exclusive) to be
filled with the specified valueval
 the value to be stored in all elements of the array
IllegalArgumentException
 if fromIndex > toIndex
ArrayIndexOutOfBoundsException
 if fromIndex < 0 or
toIndex > a.lengthpublic static void fill(int[] a, int val)
a
 the array to be filledval
 the value to be stored in all elements of the arraypublic static void fill(int[] a, int fromIndex, int toIndex, int val)
a
 the array to be filledfromIndex
 the index of the first element (inclusive) to be
filled with the specified valuetoIndex
 the index of the last element (exclusive) to be
filled with the specified valueval
 the value to be stored in all elements of the array
IllegalArgumentException
 if fromIndex > toIndex
ArrayIndexOutOfBoundsException
 if fromIndex < 0 or
toIndex > a.lengthpublic static void fill(short[] a, short val)
a
 the array to be filledval
 the value to be stored in all elements of the arraypublic static void fill(short[] a, int fromIndex, int toIndex, short val)
a
 the array to be filledfromIndex
 the index of the first element (inclusive) to be
filled with the specified valuetoIndex
 the index of the last element (exclusive) to be
filled with the specified valueval
 the value to be stored in all elements of the array
IllegalArgumentException
 if fromIndex > toIndex
ArrayIndexOutOfBoundsException
 if fromIndex < 0 or
toIndex > a.lengthpublic static void fill(char[] a, char val)
a
 the array to be filledval
 the value to be stored in all elements of the arraypublic static void fill(char[] a, int fromIndex, int toIndex, char val)
a
 the array to be filledfromIndex
 the index of the first element (inclusive) to be
filled with the specified valuetoIndex
 the index of the last element (exclusive) to be
filled with the specified valueval
 the value to be stored in all elements of the array
IllegalArgumentException
 if fromIndex > toIndex
ArrayIndexOutOfBoundsException
 if fromIndex < 0 or
toIndex > a.lengthpublic static void fill(byte[] a, byte val)
a
 the array to be filledval
 the value to be stored in all elements of the arraypublic static void fill(byte[] a, int fromIndex, int toIndex, byte val)
a
 the array to be filledfromIndex
 the index of the first element (inclusive) to be
filled with the specified valuetoIndex
 the index of the last element (exclusive) to be
filled with the specified valueval
 the value to be stored in all elements of the array
IllegalArgumentException
 if fromIndex > toIndex
ArrayIndexOutOfBoundsException
 if fromIndex < 0 or
toIndex > a.lengthpublic static void fill(boolean[] a, boolean val)
a
 the array to be filledval
 the value to be stored in all elements of the arraypublic static void fill(boolean[] a, int fromIndex, int toIndex, boolean val)
a
 the array to be filledfromIndex
 the index of the first element (inclusive) to be
filled with the specified valuetoIndex
 the index of the last element (exclusive) to be
filled with the specified valueval
 the value to be stored in all elements of the array
IllegalArgumentException
 if fromIndex > toIndex
ArrayIndexOutOfBoundsException
 if fromIndex < 0 or
toIndex > a.lengthpublic static void fill(double[] a, double val)
a
 the array to be filledval
 the value to be stored in all elements of the arraypublic static void fill(double[] a, int fromIndex, int toIndex, double val)
a
 the array to be filledfromIndex
 the index of the first element (inclusive) to be
filled with the specified valuetoIndex
 the index of the last element (exclusive) to be
filled with the specified valueval
 the value to be stored in all elements of the array
IllegalArgumentException
 if fromIndex > toIndex
ArrayIndexOutOfBoundsException
 if fromIndex < 0 or
toIndex > a.lengthpublic static void fill(float[] a, float val)
a
 the array to be filledval
 the value to be stored in all elements of the arraypublic static void fill(float[] a, int fromIndex, int toIndex, float val)
a
 the array to be filledfromIndex
 the index of the first element (inclusive) to be
filled with the specified valuetoIndex
 the index of the last element (exclusive) to be
filled with the specified valueval
 the value to be stored in all elements of the array
IllegalArgumentException
 if fromIndex > toIndex
ArrayIndexOutOfBoundsException
 if fromIndex < 0 or
toIndex > a.lengthpublic static void fill(Object[] a, Object val)
a
 the array to be filledval
 the value to be stored in all elements of the array
ArrayStoreException
 if the specified value is not of a
runtime type that can be stored in the specified arraypublic static void fill(Object[] a, int fromIndex, int toIndex, Object val)
a
 the array to be filledfromIndex
 the index of the first element (inclusive) to be
filled with the specified valuetoIndex
 the index of the last element (exclusive) to be
filled with the specified valueval
 the value to be stored in all elements of the array
IllegalArgumentException
 if fromIndex > toIndex
ArrayIndexOutOfBoundsException
 if fromIndex < 0 or
toIndex > a.length
ArrayStoreException
 if the specified value is not of a
runtime type that can be stored in the specified arraypublic static <T> T[] copyOf(T[] original, int newLength)
original
 the array to be copiednewLength
 the length of the copy to be returned
NegativeArraySizeException
 if newLength is negative
NullPointerException
 if original is nullpublic static <T,U> T[] copyOf(U[] original, int newLength, Class<? extends T[]> newType)
original
 the array to be copiednewLength
 the length of the copy to be returnednewType
 the class of the copy to be returned
NegativeArraySizeException
 if newLength is negative
NullPointerException
 if original is null
ArrayStoreException
 if an element copied from
original is not of a runtime type that can be stored in
an array of class newTypepublic static byte[] copyOf(byte[] original, int newLength)
original
 the array to be copiednewLength
 the length of the copy to be returned
NegativeArraySizeException
 if newLength is negative
NullPointerException
 if original is nullpublic static short[] copyOf(short[] original, int newLength)
original
 the array to be copiednewLength
 the length of the copy to be returned
NegativeArraySizeException
 if newLength is negative
NullPointerException
 if original is nullpublic static int[] copyOf(int[] original, int newLength)
original
 the array to be copiednewLength
 the length of the copy to be returned
NegativeArraySizeException
 if newLength is negative
NullPointerException
 if original is nullpublic static long[] copyOf(long[] original, int newLength)
original
 the array to be copiednewLength
 the length of the copy to be returned
NegativeArraySizeException
 if newLength is negative
NullPointerException
 if original is nullpublic static char[] copyOf(char[] original, int newLength)
original
 the array to be copiednewLength
 the length of the copy to be returned
NegativeArraySizeException
 if newLength is negative
NullPointerException
 if original is nullpublic static float[] copyOf(float[] original, int newLength)
original
 the array to be copiednewLength
 the length of the copy to be returned
NegativeArraySizeException
 if newLength is negative
NullPointerException
 if original is nullpublic static double[] copyOf(double[] original, int newLength)
original
 the array to be copiednewLength
 the length of the copy to be returned
NegativeArraySizeException
 if newLength is negative
NullPointerException
 if original is nullpublic static boolean[] copyOf(boolean[] original, int newLength)
original
 the array to be copiednewLength
 the length of the copy to be returned
NegativeArraySizeException
 if newLength is negative
NullPointerException
 if original is nullpublic static <T> T[] copyOfRange(T[] original, int from, int to)
The resulting array is of exactly the same class as the original array.
original
 the array from which a range is to be copiedfrom
 the initial index of the range to be copied, inclusiveto
 the final index of the range to be copied, exclusive.
(This index may lie outside the array.)
ArrayIndexOutOfBoundsException
 if from < 0
or from > original.length()
IllegalArgumentException
 if from > to
NullPointerException
 if original is nullpublic static <T,U> T[] copyOfRange(U[] original, int from, int to, Class<? extends T[]> newType)
original
 the array from which a range is to be copiedfrom
 the initial index of the range to be copied, inclusiveto
 the final index of the range to be copied, exclusive.
(This index may lie outside the array.)newType
 the class of the copy to be returned
ArrayIndexOutOfBoundsException
 if from < 0
or from > original.length()
IllegalArgumentException
 if from > to
NullPointerException
 if original is null
ArrayStoreException
 if an element copied from
original is not of a runtime type that can be stored in
an array of class newType.public static byte[] copyOfRange(byte[] original, int from, int to)
original
 the array from which a range is to be copiedfrom
 the initial index of the range to be copied, inclusiveto
 the final index of the range to be copied, exclusive.
(This index may lie outside the array.)
ArrayIndexOutOfBoundsException
 if from < 0
or from > original.length()
IllegalArgumentException
 if from > to
NullPointerException
 if original is nullpublic static short[] copyOfRange(short[] original, int from, int to)
original
 the array from which a range is to be copiedfrom
 the initial index of the range to be copied, inclusiveto
 the final index of the range to be copied, exclusive.
(This index may lie outside the array.)
ArrayIndexOutOfBoundsException
 if from < 0
or from > original.length()
IllegalArgumentException
 if from > to
NullPointerException
 if original is nullpublic static int[] copyOfRange(int[] original, int from, int to)
original
 the array from which a range is to be copiedfrom
 the initial index of the range to be copied, inclusiveto
 the final index of the range to be copied, exclusive.
(This index may lie outside the array.)
ArrayIndexOutOfBoundsException
 if from < 0
or from > original.length()
IllegalArgumentException
 if from > to
NullPointerException
 if original is nullpublic static long[] copyOfRange(long[] original, int from, int to)
original
 the array from which a range is to be copiedfrom
 the initial index of the range to be copied, inclusiveto
 the final index of the range to be copied, exclusive.
(This index may lie outside the array.)
ArrayIndexOutOfBoundsException
 if from < 0
or from > original.length()
IllegalArgumentException
 if from > to
NullPointerException
 if original is nullpublic static char[] copyOfRange(char[] original, int from, int to)
original
 the array from which a range is to be copiedfrom
 the initial index of the range to be copied, inclusiveto
 the final index of the range to be copied, exclusive.
(This index may lie outside the array.)
ArrayIndexOutOfBoundsException
 if from < 0
or from > original.length()
IllegalArgumentException
 if from > to
NullPointerException
 if original is nullpublic static float[] copyOfRange(float[] original, int from, int to)
original
 the array from which a range is to be copiedfrom
 the initial index of the range to be copied, inclusiveto
 the final index of the range to be copied, exclusive.
(This index may lie outside the array.)
ArrayIndexOutOfBoundsException
 if from < 0
or from > original.length()
IllegalArgumentException
 if from > to
NullPointerException
 if original is nullpublic static double[] copyOfRange(double[] original, int from, int to)
original
 the array from which a range is to be copiedfrom
 the initial index of the range to be copied, inclusiveto
 the final index of the range to be copied, exclusive.
(This index may lie outside the array.)
ArrayIndexOutOfBoundsException
 if from < 0
or from > original.length()
IllegalArgumentException
 if from > to
NullPointerException
 if original is nullpublic static boolean[] copyOfRange(boolean[] original, int from, int to)
original
 the array from which a range is to be copiedfrom
 the initial index of the range to be copied, inclusiveto
 the final index of the range to be copied, exclusive.
(This index may lie outside the array.)
ArrayIndexOutOfBoundsException
 if from < 0
or from > original.length()
IllegalArgumentException
 if from > to
NullPointerException
 if original is nullpublic static <T> List<T> asList(T... a)
Collection.toArray()
. The returned list is
serializable and implements RandomAccess
.
This method also provides a convenient way to create a fixedsize list initialized to contain several elements:
List<String> stooges = Arrays.asList("Larry", "Moe", "Curly");
a
 the array by which the list will be backed
public static int hashCode(long[] a)
The value returned by this method is the same value that would be
obtained by invoking the hashCode
method on a List
containing a sequence of Long
instances representing the elements of a in the same order.
If a is null, this method returns 0.
a
 the array whose hash value to compute
public static int hashCode(int[] a)
The value returned by this method is the same value that would be
obtained by invoking the hashCode
method on a List
containing a sequence of Integer
instances representing the elements of a in the same order.
If a is null, this method returns 0.
a
 the array whose hash value to compute
public static int hashCode(short[] a)
The value returned by this method is the same value that would be
obtained by invoking the hashCode
method on a List
containing a sequence of Short
instances representing the elements of a in the same order.
If a is null, this method returns 0.
a
 the array whose hash value to compute
public static int hashCode(char[] a)
The value returned by this method is the same value that would be
obtained by invoking the hashCode
method on a List
containing a sequence of Character
instances representing the elements of a in the same order.
If a is null, this method returns 0.
a
 the array whose hash value to compute
public static int hashCode(byte[] a)
The value returned by this method is the same value that would be
obtained by invoking the hashCode
method on a List
containing a sequence of Byte
instances representing the elements of a in the same order.
If a is null, this method returns 0.
a
 the array whose hash value to compute
public static int hashCode(boolean[] a)
The value returned by this method is the same value that would be
obtained by invoking the hashCode
method on a List
containing a sequence of Boolean
instances representing the elements of a in the same order.
If a is null, this method returns 0.
a
 the array whose hash value to compute
public static int hashCode(float[] a)
The value returned by this method is the same value that would be
obtained by invoking the hashCode
method on a List
containing a sequence of Float
instances representing the elements of a in the same order.
If a is null, this method returns 0.
a
 the array whose hash value to compute
public static int hashCode(double[] a)
The value returned by this method is the same value that would be
obtained by invoking the hashCode
method on a List
containing a sequence of Double
instances representing the elements of a in the same order.
If a is null, this method returns 0.
a
 the array whose hash value to compute
public static int hashCode(Object[] a)
For any two arrays a and b such that Arrays.equals(a, b), it is also the case that Arrays.hashCode(a) == Arrays.hashCode(b).
The value returned by this method is equal to the value that would be returned by Arrays.asList(a).hashCode(), unless a is null, in which case 0 is returned.
a
 the array whose contentbased hash code to compute
deepHashCode(Object[])
public static int deepHashCode(Object[] a)
For any two arrays a and b such that Arrays.deepEquals(a, b), it is also the case that Arrays.deepHashCode(a) == Arrays.deepHashCode(b).
The computation of the value returned by this method is similar to
that of the value returned by List.hashCode()
on a list
containing the same elements as a in the same order, with one
difference: If an element e of a is itself an array,
its hash code is computed not by calling e.hashCode(), but as
by calling the appropriate overloading of Arrays.hashCode(e)
if e is an array of a primitive type, or as by calling
Arrays.deepHashCode(e) recursively if e is an array
of a reference type. If a is null, this method
returns 0.
a
 the array whose deepcontentbased hash code to compute
hashCode(Object[])
public static boolean deepEquals(Object[] a1, Object[] a2)
equals(Object[],Object[])
method, this method is appropriate for use with nested arrays of
arbitrary depth.
Two array references are considered deeply equal if both are null, or if they refer to arrays that contain the same number of elements and all corresponding pairs of elements in the two arrays are deeply equal.
Two possibly null elements e1 and e2 are deeply equal if any of the following conditions hold:
If either of the specified arrays contain themselves as elements either directly or indirectly through one or more levels of arrays, the behavior of this method is undefined.
a1
 one array to be tested for equalitya2
 the other array to be tested for equality
equals(Object[],Object[])
public static String toString(long[] a)
a
 the array whose string representation to return
public static String toString(int[] a)
a
 the array whose string representation to return
public static String toString(short[] a)
a
 the array whose string representation to return
public static String toString(char[] a)
a
 the array whose string representation to return
public static String toString(byte[] a)
a
 the array whose string representation to return
public static String toString(boolean[] a)
a
 the array whose string representation to return
public static String toString(float[] a)
a
 the array whose string representation to return
public static String toString(double[] a)
a
 the array whose string representation to return
public static String toString(Object[] a)
Object.toString()
method inherited from
Object, which describes their identities rather than
their contents.
The value returned by this method is equal to the value that would be returned by Arrays.asList(a).toString(), unless a is null, in which case "null" is returned.
a
 the array whose string representation to return
deepToString(Object[])
public static String deepToString(Object[] a)
The string representation consists of a list of the array's elements, enclosed in square brackets ("[]"). Adjacent elements are separated by the characters ", " (a comma followed by a space). Elements are converted to strings as by String.valueOf(Object), unless they are themselves arrays.
If an element e is an array of a primitive type, it is converted to a string as by invoking the appropriate overloading of Arrays.toString(e). If an element e is an array of a reference type, it is converted to a string as by invoking this method recursively.
To avoid infinite recursion, if the specified array contains itself as an element, or contains an indirect reference to itself through one or more levels of arrays, the selfreference is converted to the string "[...]". For example, an array containing only a reference to itself would be rendered as "[[...]]".
This method returns "null" if the specified array is null.
a
 the array whose string representation to return
toString(Object[])