How to search element in Character Array using Index in Java?

Declaration :

public static int binarySearch(char[] a, int fromIndex, int toIndex, char key)

1	public static int binarySearch(char[] a, int fromIndex, int toIndex, char key)

Explanation :

Purpose	The java.util.Arrays.binarySearch(char[] a int fromIndex int toIndex char key) method searches a range of the specified array of chars for the specified value using the binary search algorithm. The range must be sorted before making this call.If it is not sorted the results are undefined.
Parameters	a ===> This is the array to be searched.
	fromIndex ===> This is the index of the first element (inclusive) to be searched.
	toIndex ===> This is the index of the last element (exclusive) to be searched.
	key ===> This is the value to be searched for.
Return Value	This method returns index of the search key if it is contained in the array else it returns (-(insertion point) – 1). The insertion point is 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.
Exception	IllegalArgumentException — if fromIndex > toIndex ,ArrayIndexOutOfBoundsException — if fromIndex < 0 or toIndex > a.length

Java Program : Example

Below example will explain java.util.Arrays.binarySearch() method.

package com.c4learn;

import java.util.Arrays;

public class ArrayDemo {
	public static void main(String[] args) {

	    // Initialize unsorted char array
	    char arr[] = {'t', 'q', 's', 'r','p'};

	    // Sorting array
	    Arrays.sort(arr);

	    // Printing Sorted Array List
	    System.out.println("The sorted char array is:");
	    for (char ch : arr) {
	      System.out.println("Character = " + ch);
	    }

	    // Enter the character to be searched
	    char val = 't';

	    // Entering the range of index
	    int index = Arrays.binarySearch(arr,1,5,val);

	    System.out.println("The index of t is : " + index);
	  }

}

package com.c4learn;

import java.util.Arrays;

public class ArrayDemo {

public static void main(String[] args) {

// Initialize unsorted char array

char arr[] = {'t', 'q', 's', 'r','p'};

// Sorting array

Arrays.sort(arr);

// Printing Sorted Array List

System.out.println("The sorted char array is:");

for (char ch : arr) {

System.out.println("Character = " + ch);

}

// Enter the character to be searched

char val = 't';

// Entering the range of index

int index = Arrays.binarySearch(arr,1,5,val);

System.out.println("The index of t is : " + index);

}

Output of Program :

The sorted char array is:
Character =  p
Character =  q
Character =  r
Character =  s
Character =  t
The index of t is : 4

The sorted char array is:

Character = p

Character = q

Character = r

Character = s

Character = t

The index of t is : 4

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