Stack indexOf() method in Java with Example
The Java.util.Stack.indexOf(Object element) method is used to check and find the occurrence of a particular element in the Stack. If the element is present then the index of the first occurrence of the element is returned otherwise -1 is returned if the Stack does not contain the element.
Syntax:
Stack.indexOf(Object element)
Parameters: This method accepts a mandatory parameter element of the type of Stack. It specifies the element whose occurrence is needed to be checked in the Stack.
Return Value: This method returns the index or position of the first occurrence of the element in the Stack. Else it returns -1 if the element is not present in the Stack. The returned value is of integer type.
Below programs illustrate the Java.util.Stack.indexOf() method:
Program 1:
// Java code to illustrate indexOf() import java.util.*; public class StackDemo { public static void main(String args[]) { // Creating an empty Stack Stack<String> stack = new Stack<String>(); // Use add() method to add elements in the Stack stack.add( "Beginner" ); stack.add( "for" ); stack.add( "Beginner" ); stack.add( "10" ); stack.add( "20" ); // Displaying the Stack System.out.println( "Stack: " + stack); // The first position of an element // is returned System.out.println( "The first occurrence" + " of Beginner is at index:" + stack.indexOf( "Beginner" )); System.out.println( "The first occurrence" + " of 10 is at index: " + stack.indexOf( "10" )); } } |
Stack: [Beginner, for, Beginner, 10, 20] The first occurrence of Beginner is at index:0 The first occurrence of 10 is at index: 3
Program 2:
// Java code to illustrate indexOf() import java.util.*; public class StackDemo { public static void main(String args[]) { // Creating an empty Stack Stack<Integer> stack = new Stack<Integer>(); // Use add() method to add elements in the Stack stack.add( 1 ); stack.add( 2 ); stack.add( 3 ); stack.add( 10 ); stack.add( 20 ); // Displaying the Stack System.out.println( "Stack: " + stack); // The first position of an element // is returned System.out.println( "The first occurrence" + " of Beginner is at index:" + stack.indexOf( 2 )); System.out.println( "The first occurrence" + " of 10 is at index: " + stack.indexOf( 20 )); } } |
Stack: [1, 2, 3, 10, 20] The first occurrence of Beginner is at index:1 The first occurrence of 10 is at index: 4