The lastIndexOf() method of ArrayList in Java is used to get the index of the last occurrence of an element in an ArrayList object.
Syntax :
lastIndexOf(element)
Parameter : The element whose last index is to be returned.
Returns :
It returns the last occurrence of the element passed in the parameter. It returns -1 if the element is not found.
Program to demonstrate the working of lastIndexOf():
// Java code to demonstrate the working of// lastIndexOf() method in ArrayList  // for ArrayList functionsimport java.util.ArrayList;  public class GFG {    public static void main(String[] args)    {          // creating an Empty Integer ArrayList        ArrayList<Integer> arr = new ArrayList<Integer>(7);          // using add() to initialize values        arr.add(10);        arr.add(20);        arr.add(30);        arr.add(40);        arr.add(30);        arr.add(30);        arr.add(40);          System.out.println("The list initially " + arr);          // last index of 30          int element = arr.lastIndexOf(30);        if (element != -1)            System.out.println("the lastIndexof of" +                              " 30 is " + element);        else            System.out.println("30 is not present in" +                                         " the list");          // last index of 100        element = arr.lastIndexOf(100);        if (element != -1)            System.out.println("the lastIndexof of 100" +                                       " is " + element);        else            System.out.println("100 is not present in" +                                            " the list");    }} |
Output :
The list initially [10, 20, 30, 40, 30, 30, 40] the lastIndexof of 30 is 5 100 is not present in the list
