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

Declaration :

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

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

Explanation :

Purpose	The java.util.Arrays.binarySearch(double[] a int fromIndex int toIndex double key) method searches a range of the specified array of doubles 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 double array
		double arr[] = { 9.9, 4.4, 2.2, 7.7, 5.5 };
		// Sorting array
		Arrays.sort(arr);
		// Printing Sorted Double Array List
		System.out.println("The sorted double array is:");
		for (double num : arr) {
			System.out.println("Array Element is " + num);
		}
		// Entering the value to be searched
		double val = 7.7;
		// Enter the range of index
		int returnV = Arrays.binarySearch(arr, 0, 5, val);
		System.out.println("The index of element 7.7 is : " + returnV);
	}
}

package com.c4learn;

import java.util.Arrays;

public class ArrayDemo {

public static void main(String[] args) {

// Initialize unsorted double array

double arr[] = { 9.9, 4.4, 2.2, 7.7, 5.5 };

// Sorting array

Arrays.sort(arr);

// Printing Sorted Double Array List

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

for (double num : arr) {

System.out.println("Array Element is " + num);

}

// Entering the value to be searched

double val = 7.7;

// Enter the range of index

int returnV = Arrays.binarySearch(arr, 0, 5, val);

System.out.println("The index of element 7.7 is : " + returnV);

}

Output of Program :

The sorted double array is:
Array Element is 2.2
Array Element is 4.4
Array Element is 5.5
Array Element is 7.7
Array Element is 9.9
The index of element 7.7 is : 3

The sorted double array is:

Array Element is 2.2

Array Element is 4.4

Array Element is 5.5

Array Element is 7.7

Array Element is 9.9

The index of element 7.7 is : 3

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