Aug 8, 2018

Arrays.fill() in Java with Examples

java.util.Arrays.fill() method is in java.util.Arrays class. This method assigns the specified data type value to each element of the specified range of the specified array.

Syntax:
// Makes all elements of a[] equal to "val"
public static void fill(int[] a, int val)

// Makes elements from from_Index (inclusive) to to_Index
// (exclusive) equal to "val"
public static void fill(int[] a, int from_Index, int to_Index, int val)

This method doesn't return any value.

Exceptions it Throws:
IllegalArgumentException - if from_Index > to_Index
ArrayIndexOutOfBoundsException - if from_Index  a.length

Examples:

We can fill entire array:

// Java program to fill a subarray of given array
import java.util.Arrays;

public class Main
{
    public static void main(String[] args)
    {
        int ar[] = {2, 2, 1, 8, 3, 2, 2, 4, 2};

        // To fill complete array with a particular
        // value
        Arrays.fill(ar, 10);
        System.out.println("Array completely filled" +
                  " with 10\n" + Arrays.toString(ar));
    }
}

or from specific index

public static void fill(Object[] a,
        int fromIndex,
        int toIndex,
        Object val)