Java - Bulk Initialize an Array with Arrays.fill()

Introduces the Arrays.fill() method, which is used to initialize an array in bulk.
Tags:

Bulk Array Initialization - Arrays.fill()

In Java, there are cases where you need to put the same value into an array in bulk when initializing it.

Usually, you might think of a method like the following, but this method looks too inefficient.


package com.devkuma.basic.array;

import java.util.Arrays;

public class ArrayFill1 {
    public static void main(String args[]) {
        int[] arr = new int[5];
        for (int i = 0; i < arr.length; i++) {
            arr[i] = 10;
        }
        System.out.println(Arrays.toString(arr));
    }
}

Execution result:

[10, 10, 10, 10, 10]

Java provides the Arrays.fill() method for this situation.

If you apply the Arrays.fill() method to the code above, it can be changed as follows.

package com.devkuma.basic.array;

import java.util.Arrays;

public class ArrayFill1 {
    public static void main(String args[]) {
        int[] arr = new int[5];
        Arrays.fill(arr, 10);
        System.out.println(Arrays.toString(arr));
    }
}

Execution result:

[10, 10, 10, 10, 10]