Get the index of an element

ReturnMethodSummary
intindexOf(Object o)Returns the index of the first occurrence of the specified element in this list, or -1 if this list does not contain the element.
intlastIndexOf(Object o)Returns the index of the last occurrence of the specified element in this list, or -1 if this list does not contain the element.

  import java.util.LinkedList;

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

        ll.add("A");
        ll.add("java2s.com");
        ll.add("B");
        ll.add("C");
        ll.add("java2s.com");


        System.out.println(ll.indexOf("java2s.com"));
        System.out.println(ll.lastIndexOf("java2s.com"));

    }
}

The output:


1
4

Search elements of LinkedList


import java.util.LinkedList;

public class Main {
  public static void main(String[] args) {
    LinkedList lList = new LinkedList();
    lList.add("1");
    lList.add("2");
    lList.add("3");
    lList.add("4");
    lList.add("5");
    lList.add("java2s.com");
    int index = lList.indexOf("2");
    if (index != -1) {
      System.out.println("First index of 2: " + index);
    } else {
      System.out.println("LinkedList does not contain 2");
    }
    index = lList.lastIndexOf("2");
    if (index != -1) {
      System.out.println("Last index of 2: " + index);
    } else {
      System.out.println("LinkedList does not contain 2");
    }
  }
}

The output:


First index of 2: 1
Last index of 2: 1
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