The ```Stack<T>``` generic class in the ```System.Collections.Generic``` namespace provides the **```Clear()```** method, which can be used to remove all the elements of a stack in C#.

#   
#  Syntax
```
public void Clear ();
```

##  
## Things to note
- Other object references from elements of ```Stack<T>``` are also released after the ```Clear()``` method is called.

- The stack's ```Count``` property becomes `0` after the ```Clear()``` method is called.

- This method does not change the *capacity* of the stack.

- This method changes the *state* of the stack.

- This is an _O(n)_ operation, where $n$ is the count of elements.



#   
## Code

In the following code, we create a stack of strings.

First, we call the ```Push()``` method with the strings `Asia`, `Africa`, and `Europe`. This inserts these three strings onto the stack, with `Europe` at the top of the stack. 

We display all the stack elements, and we can see that it has three elements in it.

We then call the ```Clear()``` method and print the count of the stack. We also display all elements of the stack. As we can observe in the output, the stack does not have any elements, and `count` is set to zero.

using System;
using System.Collections.Generic;

class StackClear
{
    static void Main()
    {
        Stack<string> stack = new Stack<string>();
        stack.Push("Asia");
        stack.Push("Africa");     
        stack.Push("Europe");  
        Console.WriteLine("Current Stack Items: \n{0}\n", string.Join(",", stack.ToArray()));
        
        stack.Clear();
        Console.WriteLine("Stack Count Ater Clear(): {0}", stack.Count);
        Console.WriteLine("Stack Items After Clear():\n{0}", string.Join(",", stack.ToArray()));
    }
}

How to remove all elements from a stack in C#

Use Stack<T>.Clear() in C# to remove all elements, reset count to 0, but retain capacity.