jsimple.util

Class Arrays

java.lang.Object

jsimple.util.Arrays

public class Arrays
extends java.lang.Object

Arrays contains static methods which operate on arrays.

Method Summary

Modifier and Type	Method and Description
static <T> int	binarySearch(T[] array, int startIndex, int endIndex, T object, Comparator<T> comparator) Performs a binary search for the specified element in a part of the specified sorted array using the Comparator to compare elements.
static <T> int	binarySearch(T[] array, T object, Comparator<T> comparator) Performs a binary search for the specified element in the specified sorted array using the Comparator to compare elements.
static <T> boolean	equals(T[] array1, T[] array2) Compares the two arrays.
static <T> void	fill(T[] array, int start, int end, T value) Fills the specified range in the array with the specified element.
static <T> void	fill(T[] array, T value) Fills the specified array with the specified element.
static <T> int	hashCode(T[] array) Returns a hash code based on the contents of the given array.
static <T> void	sort(T[] array, Comparator<T> comparator) Sorts the specified array using the specified Comparator.
static <T> void	sort(T[] array, int start, int end, Comparator<T> comparator) Sorts the specified array range, from start (inclusive) to end (exclusive), using the specified Comparator.
static <T> java.lang.String	toString(T[] array) Creates a String representation of the array passed.

Methods inherited from class java.lang.Object

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

Method Detail

binarySearch

public static <T> int binarySearch(T[] array,
                                   T object,
                                   Comparator<T> comparator)

Performs a binary search for the specified element in the specified sorted array using the Comparator to compare elements.

Type Parameters:

T - type of object

Parameters:

array - the sorted array to search

object - the element to find

comparator - the Comparator

Returns:

the non-negative index of the element, or a negative index which is the -index - 1 where the element would be inserted

binarySearch

public static <T> int binarySearch(T[] array,
                                   int startIndex,
                                   int endIndex,
                                   T object,
                                   Comparator<T> comparator)

Performs a binary search for the specified element in a part of the specified sorted array using the Comparator to compare elements.

Type Parameters:

T - type of object

Parameters:

array - the sorted array to search

startIndex - the inclusive start index

endIndex - the exclusive end index

object - the value element to find

comparator - the Comparator

Returns:

the non-negative index of the element, or a negative index which is the -index - 1 where the element would be inserted

Throws:

ProgrammerError - - if startIndex is bigger than endIndex

ProgrammerError - - if startIndex is smaller than zero or or endIndex is bigger than length of array

fill

public static <T> void fill(T[] array,
                            T value)

Fills the specified array with the specified element.

Parameters:

array - the array to fill.

value - the element to fill with

fill

public static <T> void fill(T[] array,
                            int start,
                            int end,
                            T value)

Fills the specified range in the array with the specified element.

Parameters:

array - the array to fill.

start - the first index to fill.

end - the last + 1 index to fill.

value - the element.

Throws:

ProgrammerError - if start > end.

ProgrammerError - if start < 0 or end > array.length.

hashCode

public static <T> int hashCode(T[] array)

Returns a hash code based on the contents of the given array. If the array contains other arrays as its elements, the hash code is based on their identities not their contents. So it is acceptable to invoke this method on an array that contains itself as an element, either directly or indirectly.

For any two arrays a and b, if Arrays.equals(a, b) returns true, it means that the return value of Arrays.hashCode(a) equals Arrays.hashCode(b).

The value returned by this method is the same value as the method Arrays.asList(array).hashCode(). If the array is null, the return value is 0.

Parameters:

array - the array whose hash code to compute.

Returns:

the hash code for array.

equals

public static <T> boolean equals(T[] array1,
                                 T[] array2)

Compares the two arrays.

Parameters:

array1 - the first array.

array2 - the second array.

Returns:

true if both arrays are null or if the arrays have the same length and the elements at each index in the two arrays are equal according to equals(), false otherwise.

sort

public static <T> void sort(T[] array,
                            int start,
                            int end,
                            Comparator<T> comparator)

Sorts the specified array range, from start (inclusive) to end (exclusive), using the specified Comparator.

Parameters:

array - the array to be sorted.

start - the start index to sort.

end - the last + 1 index to sort.

comparator - the Comparator.

Throws:

ProgrammerError - if start > end.

ProgrammerError - if start < 0 or end > array.length.

sort

public static <T> void sort(T[] array,
                            Comparator<T> comparator)

Sorts the specified array using the specified Comparator.

Parameters:

array - the array to be sorted

comparator - the Comparator

toString

public static <T> java.lang.String toString(T[] array)

Creates a String representation of the array passed. The result is surrounded by brackets ("[]"), each element is converted to a String via the String.valueOf(Object) and separated by ", ". If the array is null, then "null" is returned.

Parameters:

array - the array to convert.

Returns:

the String representation of array.