Java Collections - Arrays.fill() Examples

Java Collections Java Java API 

Class:

java.util.Arrays

Methods:

These methods assign the specified 'val' to each element of the specified array.

public static void fill(long[] a,
                        long val)

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

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

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

public static void fill(short[] a,
                        short val)

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

public static void fill(char[] a,
                        char val)

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

public static void fill(byte[] a,
                        byte val)

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

public static void fill(boolean[] a,
                        boolean val)

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

public static void fill(double[] a,
                        double val)

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

public static void fill(float[] a,
                        float val)

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

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

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

Examples

package com.logicbig.example.arrays;

import java.util.Arrays;

public class FillExample {

    public static void main(String... args) {
        boolean[] arr = new boolean[3];
        System.out.println(Arrays.toString(arr));

        Arrays.fill(arr, true);
        System.out.println(Arrays.toString(arr));
    }
}

Output

[false, false, false]
[true, true, true]

package com.logicbig.example.arrays;

import java.util.Arrays;

public class FillExample2 {

    public static void main(String... args) {
        int[] arr = new int[3];
        System.out.println(Arrays.toString(arr));

        Arrays.fill(arr, 5);
        System.out.println(Arrays.toString(arr));
    }
}

Output

[0, 0, 0]
[5, 5, 5]

package com.logicbig.example.arrays;

import java.util.Arrays;

public class FillExample3 {

    public static void main(String... args) {
        int[] arr = new int[3];
        System.out.println(Arrays.toString(arr));

        Arrays.fill(arr, 1, 3, 5);
        System.out.println(Arrays.toString(arr));
    }
}

Output

[0, 0, 0]
[0, 5, 5]

package com.logicbig.example.arrays;

import java.util.Arrays;

public class FillExample4 {

    public static void main(String... args) {
        char[] arr = new char[3];
        System.out.println(Arrays.toString(arr));

        Arrays.fill(arr, 'z');
        System.out.println(Arrays.toString(arr));
    }
}

Output

[ ,  ,  ]
[z, z, z]

Example of Arrays#fill(Object[], ..):

package com.logicbig.example.arrays;

import java.util.Arrays;

public class FillExample5 {

    public static void main(String... args) {
        String[] arr = new String[3];
        System.out.println(Arrays.toString(arr));

        Arrays.fill(arr, "apple");
        System.out.println(Arrays.toString(arr));

        String[] arr2 = new String[3];
        Arrays.fill(arr2, 1, 2, "apple");
        System.out.println(Arrays.toString(arr2));
    }
}

Output

[null, null, null]
[apple, apple, apple]
[null, apple, null]