Performing Binary Search on Java char Array Example

1. /*
2.   Performing Binary Search on Java char Array Example
3.   This java example shows how to perform binary search for an element
4.   of java char array using Arrays class.
5. */
6.  
7. import java.util.Arrays;
8.  
9. public class BinarySearchCharArrayExample {
10.  
11.   public static void main(String[] args) {
12.     //create char array
13.     char charArray[] = {'a','b','d','e'};
14.    
15.     /*
16.       To perform binary search on char array use
17.       int binarySearch(char[] b, char value) of Arrays class. This method searches
18.       the char array for specified char value using binary search algorithm.
19.      
20.       Please note that the char array MUST BE SORTED before it can be searched
21.       using binarySearch method.
22.      
23.       This method returns the index of the value to be searched, if found in the
24.       array.
25.       Otherwise it returns (- (X) - 1)
26.       where X is the index where the the search value would be inserted.
27.       i.e. index of first element that is grater than the search
28.       value or array.length, if all elements of an array are less
29.       than the search value.
30.     */
31.    
32.     //sort char array using Arrays.sort method
33.     Arrays.sort(charArray);
34.    
35.     //value to search
36.     char searchValue = 'b';
37.    
38.     //since 'b' is present in char array, index of it would be returned
39.     int intResult = Arrays.binarySearch(charArray,searchValue);
40.     System.out.println("Result of binary search of 'b' is : " + intResult);
41.    
42.     //lets search something which is not in char array !
43.     searchValue = 'c';
44.     intResult = Arrays.binarySearch(charArray,searchValue);
45.     System.out.println("Result of binary search of 'c' is : " + intResult);
46.  
47.   }
48. }
49.  
50. /*
51. Output would be
52. Result of binary search of 'b' is : 1
53. Result of binary search of 'c' is : -3
54. */