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
