How to increase the size of an array in Java?

Question

I want to store as many elements as desired by the user in an array. But how do I do it.

If I were to create an array, I must do so with a fixed size. Every time a

Answer 1

By using copyOf method in java.util.Arrays class String[] size will increment automatically / dynamically. In below code array size 0 after manipulation of using Arrays.copyOf the size of String array is increased to 4.

package com.google.service;

import java.util.Arrays;

public class StringArrayAutoIncrement {
    public static void main(String[] args) {
        String[] data = new String[] { "a", "b", "c", "d", "e" };
        String[] array = new String[0];// array initialize with zero
        int incrementLength = 1;
        for (int i = 0; i < data.length; i++) {
            array = Arrays.copyOf(data, i + incrementLength);// increment by +1
        }
        /**
         * values of array after increment
         */
        for (String value : array) {
            System.out.println(value);
        }
    }
}

Output:

a
b
c
d
e