C# Stack - Clear() Method

---

---

The C# stack Clear() method is used to empty the stack by removing all the elements from the stack.

When this method is executed, the count is set to zero, and references to other objects from the collection's elements are also released. This takes O(n) time complexity, where n is the count.

Syntax

Following is the syntax of the C# stack Clear() method −

public virtual void Clear ();

Parameters

This method does not accepts any parameters.

Return value

This method does not returns any value.

Example 1: Using the Clear() Method in Stack

Following is the basic example of the Clear() method to empty a stack −

    
using System; 
using System.Collections; 
class Example { 
   public static void Main() { 
      Stack myStack = new Stack(); 
      // Inserting the elements into the Stack 
      myStack.Push(1); 
      myStack.Push(2); 
      myStack.Push(3); 
      myStack.Push(4); 
      myStack.Push(5); 
      
      Console.Write("Total number of elements in the Stack are: ");       
      Console.WriteLine(myStack.Count);       
      // Removing all elements from Stack 
      myStack.Clear(); 
      
      Console.Write("Total number of elements in the Stack are: ");       
      Console.WriteLine(myStack.Count); 
   } 
}

Output

Following is the output −

Total number of elements in the Stack are: 5
Total number of elements in the Stack are: 0

Example 2: Clear All String From Stack

Let's see another example of the Clear() method to clear all the strings from the stack −

using System; 
using System.Collections; 

class Example { 
   public static void Main() { 
      Stack myStack = new Stack(); 
      // Inserting the elements into the Stack 
      myStack.Push("Hello"); 
      myStack.Push("tutorialspoint"); 
      myStack.Push("India"); 
      myStack.Push("Good to know");
      
      Console.Write("Total number of elements in the Stack are: ");       
      Console.WriteLine(myStack.Count); 
      
      // Removing all elements from Stack 
      myStack.Clear(); 
      
      Console.Write("Total number of elements in the Stack are: ");      
      Console.WriteLine(myStack.Count); 
   }
}

Output

Following is the output −

Total number of elements in the Stack are: 4
Total number of elements in the Stack are: 0

Example 3: Clear a Person Object from Stack

The below example creates a person object. Here, we use the Clear() method to clear all the details of people from the person object −

using System;
using System.Collections.Generic;
class Person {
   public string Name { get; set; }
   public int Age { get; set; }

   public Person(string name, int age) {
      Name = name;
      Age = age;
   }

   public override string ToString() {
      return $"Name: {Name}, Age: {Age}";
   }
}
class Example {
   static void Main() {
      // Create a stack of Person objects
      Stack<Person> people = new Stack<Person>();
   
      // Push Person objects onto the stack
      people.Push(new Person("Aman", 25));
      people.Push(new Person("Gupta", 24));
      people.Push(new Person("Vivek", 26));
   
      Console.WriteLine("People stack before Clear:");
      foreach (var person in people) {
         Console.WriteLine(person);
      }
   
      // Clear the stack
      people.Clear();
   
      Console.WriteLine("\nPeople stack after Clear:");
      Console.WriteLine("Is Empty? " + (people.Count == 0 ? "Yes" : "No"));
   }
}

Output

Following is the output −

People stack before Clear:
Name: Vivek, Age: 26
Name: Gupta, Age: 24
Name: Aman, Age: 25

People stack after Clear:
Is Empty? Yes