Search an element of ArrayList with indexOf and lastIndexOf : ArrayList « Collections « Java Tutorial

1. Java Tutorial
2. Collections
3. ArrayList

import java.util.ArrayList;

public class Main {
  public static void main(String[] args) {
    ArrayList<String> arrayList = new ArrayList<String>();

    arrayList.add("2");
    arrayList.add("2");
    arrayList.add("3");
    arrayList.add("4");
    arrayList.add("5");
    arrayList.add("1");
    arrayList.add("2");

    System.out.println(arrayList.contains("2"));

    int index = arrayList.indexOf("4");
    if (index == -1)
      System.out.println("not contain 4");
    else
      System.out.println("4 at index :" + index);

    int lastIndex = arrayList.lastIndexOf("1");
    if (lastIndex == -1)
      System.out.println("not contain 1");
    else
      System.out.println("Last index :"+ lastIndex);
  }
}
/*true
4 at index :3
Last index :5
*/