Java ArrayList retainAll() Method

Example

import java.util.ArrayList;
public class Main {
  public static void main(String[] args) {
    ArrayList<String> cars = new ArrayList<String>();
    cars.add("Volvo");
    cars.add("BMW");
    cars.add("Ford");
    cars.add("Mazda");
    cars.add("Toyota");
    ArrayList<String> valid = new ArrayList<String>();
    valid.add("Volvo");
    valid.add("Ford");
    valid.add("Mazda");
    cars.retainAll(valid);
    System.out.println(cars);
  }
}