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" )); } } |
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" )); } } |
Stack: [10, 15, 30, 20, 5] Does the Stack contains 'Geeks'? false Does the Stack contains '4'? false Does the Stack contains 'No'? false
Attention reader! Don’t stop learning now. Get hold of all the important Java Foundation and Collections concepts with the Fundamentals of Java and Java Collections Course at a student-friendly price and become industry ready. To complete your preparation from learning a language to DS Algo and many more, please refer Complete Interview Preparation Course.