C# Online Compiler | .NET Fiddle

using System;
using System.Collections;
					
public class Program
{
	public static void Main()
	{
		Stack MyStack = new Stack(); 
		MyStack.Push(5);
		MyStack.Push(1);
		MyStack.Push(2); //last item to be pushed on stack ( means at top)
		
		//print stack using foreach loop
		Console.WriteLine("Stack After Pushing items:");
		PrintStack(MyStack);
		
		Console.WriteLine();
		//remove item from stack
		MyStack.Pop();
		
		//now check stack again
		Console.WriteLine("Stack After pop: ");
		PrintStack(MyStack);
		
		Console.WriteLine();
		
		//check if element exists using .Contains
		Console.WriteLine("5 Exists in Stack? : "+MyStack.Contains(5));		
		Console.WriteLine();
		
		//check top item using Peek method
		Console.WriteLine("Top Item of stack is : "+MyStack.Peek());	
	}
	
	//print stack method
	public static void PrintStack(Stack MyStack)
	{
		foreach(var item in MyStack)
		{
			Console.WriteLine(item);
		}
	}

}

 
using System;
using System.Collections;
                    
public class Program
{
    public static void Main()
    {
        Stack MyStack = new Stack(); 
        MyStack.Push(5);
        MyStack.Push(1);
        MyStack.Push(2); //last item to be pushed on stack ( means at top)
        
        //print stack using foreach loop
        Console.WriteLine("Stack After Pushing items:");
        PrintStack(MyStack);
        
        Console.WriteLine();
        //remove item from stack
        MyStack.Pop();
        
        //now check stack again
        Console.WriteLine("Stack After pop: ");
        PrintStack(MyStack);
        

Compilation error (line 6, col 0): String constants must end with a double quote.
Compilation error (line 8, col 0): End of statement expected.
Compilation error (line 9, col 0): Expression is not a method.
Compilation error (line 9, col 0): Expression expected.
Compilation error (line 9, col 0): Method arguments must be enclosed in parentheses.
Compilation error (line 10, col 0): End of statement expected.
Compilation error (line 11, col 0): Variable 'marks' hides a variable in an enclosing block.
Compilation error (line 12, col 0): End of statement expected.