Java Stack - indexOf() Method

The java.util.Stack.indexOf() method returns index of the first occurrence of the specified element in this stack, searching forward from specified index. It returns -1 if element is not present in the stack.

Syntax

public int indexOf(Object o, int index)

Parameters

Return Value

Returns the index of the first occurrence of the specified element in the stack, searching forward from specified index, or -1 if element is not present in the stack.

Exception

NA.

Example:

In the example below, the java.util.Stack.indexOf() method is used to find the index of first occurrence of the specified element in the stack MyStack, searching forward from specified index.

import java.util.*;

public class MyClass {
  public static void main(String[] args) {
    //creating a stack
    Stack<Integer> MyStack = new Stack<Integer>();

    //populating stack
    MyStack.push(10);
    MyStack.push(30);
    MyStack.push(20);
    MyStack.push(50);
    MyStack.push(30);

    System.out.print("30 appeared first time after index=2 at index="); 
    System.out.print(MyStack.indexOf(30, 2));
  }
}

The output of the above code will be:

30 appeared first time after index=2 at index=4