Arrays

public class Arrays extends Object

This class contains various methods for manipulating arrays (such as sorting and searching). This class also contains a static factory that allows arrays to be viewed as lists.

The methods in this class all throw a NullPointerException, if the specified array reference is null, except where noted.

The documentation for the methods contained in this class includes briefs description of the implementations. Such descriptions should be regarded as implementation notes, rather than parts of the specification. Implementors should feel free to substitute other algorithms, so long as the specification itself is adhered to. (For example, the algorithm used by sort(Object[]) does not have to be a MergeSort, but it does have to be stable.)

This class is a member of the Java Collections Framework.

Public Method Summary

static <T> List<T>	asList(T... a) Returns a fixed-size list backed by the specified array.
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(long[] a, long key) Searches the specified array of longs 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(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(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(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(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 <T> int	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 int	binarySearch(byte[] a, byte key) Searches the specified array of bytes 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 int	binarySearch(Object[] a, Object key) Searches the specified array for the specified object 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(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(char[] a, char key) Searches the specified array of chars 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(double[] a, double key) Searches the specified array of doubles for the specified value using the binary search algorithm.
static <T> int	binarySearch(T[] a, T key, Comparator<? super T> c) Searches the specified array for the specified object 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 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 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 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 <T, U> T[]	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 <T> T[]	copyOf(T[] original, int newLength) Copies the specified array, truncating or padding with nulls (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 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 double[]	copyOfRange(double[] original, int from, int to) Copies the specified range of the specified array into a new array.
static <T> T[]	copyOfRange(T[] 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 float[]	copyOfRange(float[] 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 int[]	copyOfRange(int[] original, int from, int to) Copies the specified range of the specified array into a new array.
static boolean[]	copyOfRange(boolean[] original, int from, int to) Copies the specified range of the specified array into a new array.
static <T, U> T[]	copyOfRange(U[] original, int from, int to, Class<? extends T[]> newType) 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 byte[]	copyOfRange(byte[] original, int from, int to) 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(Object[] a, Object[] a2) Returns true if the two specified arrays of Objects 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(long[] a, long[] a2) Returns true if the two specified arrays of longs 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(boolean[] a, boolean[] a2) Returns true if the two specified arrays of booleans 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(float[] a, float[] a2) Returns true if the two specified arrays of floats 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 boolean	equals(byte[] a, byte[] a2) Returns true if the two specified arrays of bytes are equal to one another.
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(float[] a, float val) Assigns the specified float value to each element of the specified array of floats.
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(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(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(Object[] a, Object val) Assigns the specified Object reference to each element of the specified array of Objects.
static void	fill(double[] a, double val) Assigns the specified double value to each element of the specified array of doubles.
static void	fill(long[] a, long val) Assigns the specified long value to each element of the specified array of longs.
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(byte[] a, byte val) Assigns the specified byte value to each element of the specified array of bytes.
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(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(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(boolean[] a, boolean val) Assigns the specified boolean value to each element of the specified array of booleans.
static void	fill(short[] a, short val) Assigns the specified short value to each element of the specified array of shorts.
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(int[] a, int val) Assigns the specified int value to each element of the specified array of ints.
static int	hashCode(byte[] a) Returns a hash code based on the contents of the specified array.
static int	hashCode(boolean[] 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(long[] 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(float[] 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 int	hashCode(Object[] 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 <T> void	parallelPrefix(T[] array, int fromIndex, int toIndex, BinaryOperator<T> op) Performs parallelPrefix(Object[], BinaryOperator) for the given subrange of the array.
static <T> void	parallelPrefix(T[] array, BinaryOperator<T> op) Cumulates, in parallel, each element of the given array in place, using the supplied function.
static void	parallelPrefix(long[] array, LongBinaryOperator op) Cumulates, in parallel, each element of the given array in place, using the supplied function.
static void	parallelPrefix(long[] array, int fromIndex, int toIndex, LongBinaryOperator op) Performs parallelPrefix(long[], LongBinaryOperator) for the given subrange of the array.
static void	parallelPrefix(int[] array, int fromIndex, int toIndex, IntBinaryOperator op) Performs parallelPrefix(int[], IntBinaryOperator) for the given subrange of the array.
static void	parallelPrefix(double[] array, int fromIndex, int toIndex, DoubleBinaryOperator op) Performs parallelPrefix(double[], DoubleBinaryOperator) for the given subrange of the array.
static void	parallelPrefix(double[] array, DoubleBinaryOperator op) Cumulates, in parallel, each element of the given array in place, using the supplied function.
static void	parallelPrefix(int[] array, IntBinaryOperator op) Cumulates, in parallel, each element of the given array in place, using the supplied function.
static void	parallelSetAll(double[] array, IntToDoubleFunction generator) Set all elements of the specified array, in parallel, using the provided generator function to compute each element.
static void	parallelSetAll(int[] array, IntUnaryOperator generator) Set all elements of the specified array, in parallel, using the provided generator function to compute each element.
static void	parallelSetAll(long[] array, IntToLongFunction generator) Set all elements of the specified array, in parallel, using the provided generator function to compute each element.
static <T> void	parallelSetAll(T[] array, IntFunction<? extends T> generator) Set all elements of the specified array, in parallel, using the provided generator function to compute each element.
static <T> void	parallelSort(T[] a, Comparator<? super T> cmp) Sorts the specified array of objects according to the order induced by the specified comparator.
static void	parallelSort(long[] a) Sorts the specified array into ascending numerical order.
static void	parallelSort(short[] a) Sorts the specified array into ascending numerical order.
static void	parallelSort(double[] a) Sorts the specified array into ascending numerical order.
static void	parallelSort(char[] a) Sorts the specified array into ascending numerical order.
static void	parallelSort(double[] a, int fromIndex, int toIndex) Sorts the specified range of the array into ascending numerical order.
static <T extends Comparable<? super T>> void	parallelSort(T[] a) Sorts the specified array of objects into ascending order, according to the {@linkplain Comparable natural ordering} of its elements.
static void	parallelSort(float[] a) Sorts the specified array into ascending numerical order.
static void	parallelSort(byte[] a) Sorts the specified array into ascending numerical order.
static void	parallelSort(char[] a, int fromIndex, int toIndex) Sorts the specified range of the array into ascending numerical order.
static void	parallelSort(int[] a) Sorts the specified array into ascending numerical order.
static void	parallelSort(long[] a, int fromIndex, int toIndex) Sorts the specified range of the array into ascending numerical order.
static void	parallelSort(float[] a, int fromIndex, int toIndex) Sorts the specified range of the array into ascending numerical order.
static void	parallelSort(int[] a, int fromIndex, int toIndex) Sorts the specified range of the array into ascending numerical order.
static void	parallelSort(byte[] a, int fromIndex, int toIndex) Sorts the specified range of the array into ascending numerical order.
static void	parallelSort(short[] a, int fromIndex, int toIndex) Sorts the specified range of the array into ascending numerical order.
static <T extends Comparable<? super T>> void	parallelSort(T[] a, int fromIndex, int toIndex) Sorts the specified range of the specified array of objects into ascending order, according to the {@linkplain Comparable natural ordering} of its elements.
static <T> void	parallelSort(T[] a, int fromIndex, int toIndex, Comparator<? super T> cmp) Sorts the specified range of the specified array of objects according to the order induced by the specified comparator.
static <T> void	setAll(T[] array, IntFunction<? extends T> generator) Set all elements of the specified array, using the provided generator function to compute each element.
static void	setAll(double[] array, IntToDoubleFunction generator) Set all elements of the specified array, using the provided generator function to compute each element.
static void	setAll(long[] array, IntToLongFunction generator) Set all elements of the specified array, using the provided generator function to compute each element.
static void	setAll(int[] array, IntUnaryOperator generator) Set all elements of the specified array, using the provided generator function to compute each element.
static <T> void	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 void	sort(int[] a) Sorts the specified array into ascending numerical order.
static void	sort(long[] a, int fromIndex, int toIndex) Sorts the specified range of the array into ascending order.
static void	sort(double[] a) Sorts the specified array into ascending numerical order.
static void	sort(short[] a) Sorts the specified array into ascending numerical order.
static void	sort(char[] a, int fromIndex, int toIndex) Sorts the specified range of the array into ascending order.
static void	sort(long[] a) Sorts the specified array into ascending numerical order.
static void	sort(float[] a, int fromIndex, int toIndex) Sorts the specified range of the array into ascending order.
static void	sort(short[] a, int fromIndex, int toIndex) Sorts the specified range of the array into ascending order.
static <T> void	sort(T[] a, Comparator<? super T> c) Sorts the specified array of objects according to the order induced by the specified comparator.
static void	sort(byte[] a) Sorts the specified array into ascending numerical order.
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 {@linkplain Comparable natural ordering} of its elements.
static void	sort(char[] a) Sorts the specified array into ascending numerical order.
static void	sort(double[] a, int fromIndex, int toIndex) Sorts the specified range of the array into ascending order.
static void	sort(Object[] a) Sorts the specified array of objects into ascending order, according to the {@linkplain Comparable natural ordering} of its elements.
static void	sort(int[] a, int fromIndex, int toIndex) Sorts the specified range of the array into ascending order.
static void	sort(byte[] a, int fromIndex, int toIndex) Sorts the specified range of the array into ascending order.
static void	sort(float[] a) Sorts the specified array into ascending numerical order.
static Spliterator.OfLong	spliterator(long[] array, int startInclusive, int endExclusive) Returns a Spliterator.OfLong covering the specified range of the specified array.
static Spliterator.OfLong	spliterator(long[] array) Returns a Spliterator.OfLong covering all of the specified array.
static Spliterator.OfDouble	spliterator(double[] array) Returns a Spliterator.OfDouble covering all of the specified array.
static Spliterator.OfInt	spliterator(int[] array, int startInclusive, int endExclusive) Returns a Spliterator.OfInt covering the specified range of the specified array.
static <T> Spliterator<T>	spliterator(T[] array) Returns a Spliterator covering all of the specified array.
static Spliterator.OfInt	spliterator(int[] array) Returns a Spliterator.OfInt covering all of the specified array.
static <T> Spliterator<T>	spliterator(T[] array, int startInclusive, int endExclusive) Returns a Spliterator covering the specified range of the specified array.
static Spliterator.OfDouble	spliterator(double[] array, int startInclusive, int endExclusive) Returns a Spliterator.OfDouble covering the specified range of the specified array.
static IntStream	stream(int[] array) Returns a sequential IntStream with the specified array as its source.
static LongStream	stream(long[] array) Returns a sequential LongStream with the specified array as its source.
static <T> Stream<T>	stream(T[] array) Returns a sequential Stream with the specified array as its source.
static DoubleStream	stream(double[] array, int startInclusive, int endExclusive) Returns a sequential DoubleStream with the specified range of the specified array as its source.
static DoubleStream	stream(double[] array) Returns a sequential DoubleStream with the specified array as its source.
static IntStream	stream(int[] array, int startInclusive, int endExclusive) Returns a sequential IntStream with the specified range of the specified array as its source.
static <T> Stream<T>	stream(T[] array, int startInclusive, int endExclusive) Returns a sequential Stream with the specified range of the specified array as its source.
static LongStream	stream(long[] array, int startInclusive, int endExclusive) Returns a sequential LongStream with the specified range of the specified array as its source.
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(Object[] 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(boolean[] 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(short[] 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(byte[] a) Returns a string representation of the contents of the specified array.

Inherited Method Summary

From class java.lang.Object

Object	clone() Creates and returns a copy of this Object.
boolean	equals(Object obj) Compares this instance with the specified object and indicates if they are equal.
void	finalize() Invoked when the garbage collector has detected that this instance is no longer reachable.
final Class<?>	getClass() Returns the unique instance of Class that represents this object's class.
int	hashCode() Returns an integer hash code for this object.
final void	notify() Causes a thread which is waiting on this object's monitor (by means of calling one of the wait() methods) to be woken up.
final void	notifyAll() Causes all threads which are waiting on this object's monitor (by means of calling one of the wait() methods) to be woken up.
String	toString() Returns a string containing a concise, human-readable description of this object.
final void	wait(long timeout, int nanos) Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the specified timeout expires.
final void	wait(long timeout) Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object or until the specified timeout expires.
final void	wait() Causes the calling thread to wait until another thread calls the notify() or notifyAll() method of this object.

Public Methods

public static List<T> asList (T... a)

Returns a fixed-size list backed by the specified array. (Changes to the returned list "write through" to the array.) This method acts as bridge between array-based and collection-based APIs, in combination with Collection.toArray(). The returned list is serializable and implements RandomAccess.

This method also provides a convenient way to create a fixed-size list initialized to contain several elements:

     List<String> stooges = Arrays.asList("Larry", "Moe", "Curly");
 

Parameters

a	the array by which the list will be backed

Returns

• a list view of the specified array

public 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. The range must be sorted (as by the 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.

Parameters

a	the array to be searched
fromIndex	the index of the first element (inclusive) to be searched
toIndex	the index of the last element (exclusive) to be searched
key	the value to be searched for

Returns

• index of the search key, if it is contained in the array within the specified range; otherwise, (-(insertion point) - 1). The insertion point is defined as the point at which the key would be inserted into the array: the index of the first element in the range greater than the key, or toIndex if all elements in the range are less than the specified key. Note that this guarantees that the return value will be >= 0 if and only if the key is found.

Throws

IllegalArgumentException	if fromIndex > toIndex
ArrayIndexOutOfBoundsException	if fromIndex < 0 or toIndex > a.length

public static int binarySearch (long[] a, long key)

Searches the specified array of longs for the specified value using the binary search algorithm. The array must be sorted (as by the 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.

Parameters

a	the array to be searched
key	the value to be searched for

Returns

• index of the search key, if it is contained in the array; otherwise, (-(insertion point) - 1). The insertion point is defined as the point at which the key would be inserted into the array: the index of the first element greater than the key, or a.length if all elements in the array are less than the specified key. Note that this guarantees that the return value will be >= 0 if and only if the key is found.

public 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. The range must be sorted (as by the 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.

Parameters

a	the array to be searched
fromIndex	the index of the first element (inclusive) to be searched
toIndex	the index of the last element (exclusive) to be searched
key	the value to be searched for

Returns

• index of the search key, if it is contained in the array within the specified range; otherwise, (-(insertion point) - 1). The insertion point is defined as the point at which the key would be inserted into the array: the index of the first element in the range greater than the key, or toIndex if all elements in the range are less than the specified key. Note that this guarantees that the return value will be >= 0 if and only if the key is found.

Throws

IllegalArgumentException	if fromIndex > toIndex
ArrayIndexOutOfBoundsException	if fromIndex < 0 or toIndex > a.length

public 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. The range must be sorted (as by the 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.

Parameters

a	the array to be searched
fromIndex	the index of the first element (inclusive) to be searched
toIndex	the index of the last element (exclusive) to be searched
key	the value to be searched for

Returns

• index of the search key, if it is contained in the array within the specified range; otherwise, (-(insertion point) - 1). The insertion point is defined as the point at which the key would be inserted into the array: the index of the first element in the range greater than the key, or toIndex if all elements in the range are less than the specified key. Note that this guarantees that the return value will be >= 0 if and only if the key is found.

Throws

IllegalArgumentException	if fromIndex > toIndex
ArrayIndexOutOfBoundsException	if fromIndex < 0 or toIndex > a.length

public 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. The range must be sorted (as by the 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.

Parameters

a	the array to be searched
fromIndex	the index of the first element (inclusive) to be searched
toIndex	the index of the last element (exclusive) to be searched
key	the value to be searched for

Returns

• index of the search key, if it is contained in the array within the specified range; otherwise, (-(insertion point) - 1). The insertion point is defined as the point at which the key would be inserted into the array: the index of the first element in the range greater than the key, or toIndex if all elements in the range are less than the specified key. Note that this guarantees that the return value will be >= 0 if and only if the key is found.

Throws

IllegalArgumentException	if fromIndex > toIndex
ArrayIndexOutOfBoundsException	if fromIndex < 0 or toIndex > a.length

public 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. The range must be sorted (as by the 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.

Parameters

a	the array to be searched
fromIndex	the index of the first element (inclusive) to be searched
toIndex	the index of the last element (exclusive) to be searched
key	the value to be searched for

Returns

• index of the search key, if it is contained in the array within the specified range; otherwise, (-(insertion point) - 1). The insertion point is defined as the point at which the key would be inserted into the array: the index of the first element in the range greater than the key, or toIndex if all elements in the range are less than the specified key. Note that this guarantees that the return value will be >= 0 if and only if the key is found.

Throws

IllegalArgumentException	if fromIndex > toIndex
ArrayIndexOutOfBoundsException	if fromIndex < 0 or toIndex > a.length

public 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. The range must be sorted (as by the 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.

Parameters

a	the array to be searched
fromIndex	the index of the first element (inclusive) to be searched
toIndex	the index of the last element (exclusive) to be searched
key	the value to be searched for

Returns

• index of the search key, if it is contained in the array within the specified range; otherwise, (-(insertion point) - 1). The insertion point is defined as the point at which the key would be inserted into the array: the index of the first element in the range greater than the key, or toIndex if all elements in the range are less than the specified key. Note that this guarantees that the return value will be >= 0 if and only if the key is found.

Throws

IllegalArgumentException	if fromIndex > toIndex
ArrayIndexOutOfBoundsException	if fromIndex < 0 or toIndex > a.length

public static int 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. The range must be sorted into ascending order according to the specified comparator (as by the 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.

Parameters

a	the array to be searched
fromIndex	the index of the first element (inclusive) to be searched
toIndex	the index of the last element (exclusive) to be searched
key	the value to be searched for
c	the comparator by which the array is ordered. A null value indicates that the elements' {@linkplain Comparable natural ordering} should be used.

Returns

• index of the search key, if it is contained in the array within the specified range; otherwise, (-(insertion point) - 1). The insertion point is defined as the point at which the key would be inserted into the array: the index of the first element in the range greater than the key, or toIndex if all elements in the range are less than the specified key. Note that this guarantees that the return value will be >= 0 if and only if the key is found.

Throws

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 int binarySearch (byte[] a, byte key)

Searches the specified array of bytes for the specified value using the binary search algorithm. The array must be sorted (as by the 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.

Parameters

a	the array to be searched
key	the value to be searched for

Returns

• index of the search key, if it is contained in the array; otherwise, (-(insertion point) - 1). The insertion point is defined as the point at which the key would be inserted into the array: the index of the first element greater than the key, or a.length if all elements in the array are less than the specified key. Note that this guarantees that the return value will be >= 0 if and only if the key is found.

public static int binarySearch (short[] a, short key)

Searches the specified array of shorts for the specified value using the binary search algorithm. The array must be sorted (as by the 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.

Parameters

a	the array to be searched
key	the value to be searched for

Returns

• index of the search key, if it is contained in the array; otherwise, (-(insertion point) - 1). The insertion point is defined as the point at which the key would be inserted into the array: the index of the first element greater than the key, or a.length if all elements in the array are less than the specified key. Note that this guarantees that the return value will be >= 0 if and only if the key is found.

public static int binarySearch (Object[] a, Object key)

Searches the specified array for the specified object using the binary search algorithm. The array must be sorted into ascending order according to the {@linkplain Comparable natural ordering} of its elements (as by the 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.

Parameters

a	the array to be searched
key	the value to be searched for

Returns

• index of the search key, if it is contained in the array; otherwise, (-(insertion point) - 1). The insertion point is defined as the point at which the key would be inserted into the array: the index of the first element greater than the key, or a.length if all elements in the array are less than the specified key. Note that this guarantees that the return value will be >= 0 if and only if the key is found.

Throws

ClassCastException	if the search key is not comparable to the elements of the array.

public 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. The range must be sorted (as by the 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.

Parameters

a	the array to be searched
fromIndex	the index of the first element (inclusive) to be searched
toIndex	the index of the last element (exclusive) to be searched
key	the value to be searched for

Returns

• index of the search key, if it is contained in the array within the specified range; otherwise, (-(insertion point) - 1). The insertion point is defined as the point at which the key would be inserted into the array: the index of the first element in the range greater than the key, or toIndex if all elements in the range are less than the specified key. Note that this guarantees that the return value will be >= 0 if and only if the key is found.

Throws

IllegalArgumentException	if fromIndex > toIndex
ArrayIndexOutOfBoundsException	if fromIndex < 0 or toIndex > a.length

public 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. The range must be sorted into ascending order according to the {@linkplain Comparable natural ordering} of its elements (as by the 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 t