add data to array java code example

Example 1: how to append to an array in java

import java.util.Arrays;

class ArrayAppend {
    public static void main( String args[] ) {
      int[] arr = { 10, 20, 30 };
      System.out.println(Arrays.toString(arr));

      arr = Arrays.copyOf(arr, arr.length + 1);
      arr[arr.length - 1] = 40; // Assign 40 to the last element
      System.out.println(Arrays.toString(arr));
    }
}

Example 2: java add element to existing array

//original array
String[] rgb = new String[] {"red", "green"};
//new array with one more length
String[] rgb2 = new String[rgb.length + 1];
//copy the old in the new array
System.arraycopy(rgb, 0, rgb2, 0, rgb.length);
//add element to new array
rgb2[rgb.length] = "blue";
//optional: set old array to new array
rgb = rgb2;

Example 3: how to add a number to an array in java

List myList = new ArrayList();
myList.add(5);
myList.add(7);

Example 4: how to add objects in array java

car redCar = new Car("Red");
car Garage [] = new Car [100];
Garage[0] = redCar;