C# | Check if a Stack contains an element

Last Updated : 01 Feb, 2019

Stack represents a last-in, first out collection of object.
Stack<T>.Contains(Object) Method is used to check whether an element is in the Stack<T> or not.

Syntax:

public virtual bool Contains(object obj);

Return Value: The function returns True if the element exists in the Stack<T> and returns False if the element doesn’t exist in the Stack.

Below given are some examples to understand the implementation in a better way:

Example 1:

// C# code to Check if a Stack 
// contains an element 
using System; 
using System.Collections.Generic; 
  
class GFG { 
  
    // Driver code 
    public static void Main() 
    { 
  
        // Creating a Stack of strings 
        Stack<string> myStack = new Stack<string>(); 
  
        // Inserting the elements into the Stack 
        myStack.Push("Geeks"); 
        myStack.Push("Geeks Classes"); 
        myStack.Push("Noida"); 
        myStack.Push("Data Structures"); 
        myStack.Push("GeeksforGeeks"); 
  
        // Checking whether the element is 
        // present in the Stack or not 
        // The function returns True if the 
        // element is present in the Stack, else 
        // returns False 
        Console.WriteLine(myStack.Contains("GeeksforGeeks")); 
    } 
} 

Output:

True

Example 2:

// C# code to Check if a Stack 
// contains an element 
using System; 
using System.Collections.Generic; 
  
class GFG { 
  
    // Driver code 
    public static void Main() 
    { 
  
        // Creating a Stack of Integers 
        Stack<int> myStack = new Stack<int>(); 
  
        // Inserting the elements into the Stack 
        myStack.Push(5); 
        myStack.Push(10); 
        myStack.Push(15); 
        myStack.Push(20); 
        myStack.Push(25); 
  
        // Checking whether the element is 
        // present in the Stack or not 
        // The function returns True if the 
        // element is present in the Stack, else 
        // returns False 
        Console.WriteLine(myStack.Contains(7)); 
    } 
} 