Get the number of elements contained in the Stack in C#

The Count property in C# provides an efficient way to get the number of elements contained in a Stack<T>. This property returns an integer value representing the current number of items stored in the stack.

Syntax

Following is the syntax for using the Count property −

Stack<T> stack = new Stack<T>();
int count = stack.Count;

Return Value

The Count property returns an int value representing the number of elements in the stack. For an empty stack, it returns 0.

Using Stack Count Property

Example

using System;
using System.Collections.Generic;

public class Demo {
   public static void Main(){
      Stack<string> stack = new Stack<string>();
      stack.Push("A");
      stack.Push("B");
      stack.Push("C");
      stack.Push("D");
      stack.Push("E");
      stack.Push("F");
      stack.Push("G");
      stack.Push("H");
      Console.WriteLine("Count of elements = "+stack.Count);
      Console.WriteLine("Elements in Stack...");
      foreach (string res in stack){
         Console.WriteLine(res);
      }
      stack.Clear();
      Console.Write("Count of elements (updated) = "+stack.Count);
   }
}

The output of the above code is −

Count of elements = 8
Elements in Stack...
H
G
F
E
D
C
B
A
Count of elements (updated) = 0

Using Count with Different Data Types

Example

using System;
using System.Collections.Generic;

public class Demo {
   public static void Main(){
      Stack<int> stack = new Stack<int>();
      stack.Push(10);
      stack.Push(20);
      stack.Push(30);
      stack.Push(40);
      stack.Push(50);
      stack.Push(60);
      stack.Push(70);
      stack.Push(80);
      stack.Push(90);
      stack.Push(100);
      Console.WriteLine("Count of elements = "+stack.Count);
      Console.WriteLine("Elements in Stack...");
      foreach (int res in stack){
         Console.WriteLine(res);
      }
   }
}

The output of the above code is −

Count of elements = 10
Elements in Stack...
100
90
80
70
60
50
40
30
20
10

Dynamic Count Monitoring

Example

using System;
using System.Collections.Generic;

public class Demo {
   public static void Main(){
      Stack<string> stack = new Stack<string>();
      Console.WriteLine("Initial count: " + stack.Count);
      
      stack.Push("First");
      Console.WriteLine("After Push: " + stack.Count);
      
      stack.Push("Second");
      stack.Push("Third");
      Console.WriteLine("After adding 2 more: " + stack.Count);
      
      stack.Pop();
      Console.WriteLine("After Pop: " + stack.Count);
      
      stack.Clear();
      Console.WriteLine("After Clear: " + stack.Count);
   }
}

The output of the above code is −

Initial count: 0
After Push: 1
After adding 2 more: 3
After Pop: 2
After Clear: 0

Conclusion

The Count property provides an O(1) time complexity operation to retrieve the number of elements in a Stack<T>. It dynamically updates as elements are pushed, popped, or when the stack is cleared, making it useful for monitoring stack size and implementing conditional logic based on stack contents.