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
