Java – BinarySearch in Array- example
public class BinarySearchIntArrayExample
{
/**
* TODO
*
* @param args
*/
public static void main(String[] args)
{
// create int array
int intArray[] = { 1, 2, 4, 5 };
/*
* To perform binary search on int array use int binarySearch(int[] b, int value) of Arrays class. This method
* searches the int array for specified int value using binary search algorithm. Please note that the int array
* MUST BE SORTED before it can be searched using binarySearch method. This method returns the index of the
* value to be searched, if found in the array. Otherwise it returns (- (X) – 1) where X is the index where the
* the search value would be inserted. i.e. index of first element that is grater than the search value or
* array.length, if all elements of an array are less than the search value.
*/
// sort int array using Arrays.sort method
Arrays.sort(intArray);
// value to search
int searchValue = 2;
// since 2 is present in int array, index of it would be returned
int intResult = Arrays.binarySearch(intArray, searchValue);
System.out.println(„Result of binary search of 2 is : “ + intResult);
// lets search something which is not in int array !
searchValue = 3;
intResult = Arrays.binarySearch(intArray, searchValue);
System.out.println(„Result of binary search of 3 is : “ + intResult);
}
}
/*
* Output would be Result of binary search of 2 is : 1 Result of binary search of 3 is : -3
*/
