The java.util.Stack.contains() method is used to check whether a specific element is present in the Stack or not. So basically it is used to check if a Stack contains any particular element or not.
Syntax:
Stack.contains(Object element)
Parameters: This method takes a mandatory parameter element which is of the type of Stack. This is the element that needs to be tested if it is present in the Stack or not.
Return Value: This method returns True if the element is present in the Stack otherwise it returns False.
Below programs illustrate the Java.util.Stack.contains() method:
Program 1:
// Java code to illustrate contains()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 into the Stack stack.add("Welcome"); stack.add("To"); stack.add("Geeks"); stack.add("4"); stack.add("Geeks"); // Displaying the Stack System.out.println("Stack: " + stack); // Check for "Geeks" in the Stack System.out.println("Does the Stack contains 'Geeks'? " + stack.contains("Geeks")); // Check for "4" in the Stack System.out.println("Does the Stack contains '4'? " + stack.contains("4")); // Check if the Queue contains "No" System.out.println("Does the Stack contains 'No'? " + stack.contains("No")); }} |
Output:
Stack: [Welcome, To, Geeks, 4, Geeks] Does the Stack contains 'Geeks'? true Does the Stack contains '4'? true Does the Stack contains 'No'? false
Program 2:
// Java code to illustrate contains()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 into the Stack stack.add(10); stack.add(15); stack.add(30); stack.add(20); stack.add(5); // Displaying the Stack System.out.println("Stack: " + stack); // Check for "Geeks" in the Stack System.out.println("Does the Stack contains 'Geeks'? " + stack.contains("Geeks")); // Check for "4" in the Stack System.out.println("Does the Stack contains '4'? " + stack.contains("4")); // Check if the Stack contains "No" System.out.println("Does the Stack contains 'No'? " + stack.contains("No")); }} |
Output:
Stack: [10, 15, 30, 20, 5] Does the Stack contains 'Geeks'? false Does the Stack contains '4'? false Does the Stack contains 'No'? false