Get the index of an element

int indexOf(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.
int lastIndexOf(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
Home 
  Java Book 
    Collection  

LinkedList:
  1. LinkedList class
  2. Create LinkedList
  3. Add element to LinkedList
  4. Remove all elements from LinkedList
  5. Shallow copy of a LinkedList
  6. If contain a certain element
  7. Get iterator from LinkedList
  8. Peek the element
  9. Get the element from LinkedList
  10. Get the index of an element
  11. Poll, pop and push element to a LinkedList
  12. Remove element from a LinkedList
  13. Replace the element at the position
  14. Get the size of a LinkedList
  15. Convert LinkedList to Array
  16. Storing User-Defined Classes in Collections