Add Multiple Elements to ArrayList in Java

The following example uses the addAll() method to add multiple elements to a list in one step.

import java.util.ArrayList;
import java.util.List;

public class AddingMultipleItemsEx {

    public static void main(String[] args) {

        List < String > colours1 = new ArrayList < > ();

        colours1.add("blue");
        colours1.add("red");
        colours1.add("green");

        List < String > colours2 = new ArrayList < > ();

        colours2.add("yellow");
        colours2.add("pink");
        colours2.add("brown");

        List < String > colours3 = new ArrayList < > ();
        colours3.add("white");
        colours3.add("orange");

        colours3.addAll(colours1);
        colours3.addAll(2, colours2);

        for (String col: colours3) {

            System.out.println(col);
        }
    }
}

Output

white
orange
yellow
pink
brown
blue
red
green

Two lists are created. Later, the elements of the lists are added to the third list with the addAll() method.

colours3.addAll(colours1);

The addAll() method adds all of the elements to the end of the list.

colours3.addAll(2, colours2);

This overloaded method adds all of the elements starting at the specified position.