Get the element index

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.ArrayList;
import java.util.List;

public class Main {
  public static void main(String[] args) {
    List list = new ArrayList();

    list.add("1");
    list.add("2");
    list.add("3");

    list.add("java2s.com");

    System.out.println(list.indexOf("java2s.com"));
  }
}

The output:


3
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List:
  1. List interface
  2. Add element to List
  3. Clear a List
  4. Does it contain certain element
  5. Compare two Lists
  6. Get the element index
  7. Get Iterator from a List
  8. Remove element from List
  9. Get/set element
  10. List size and empty flag
  11. Get the sub list from a list
  12. Convert List to Array