C Sharp Sealed

C# Sealed

To apply restrictions on the class and the method in C#, the sealed keyword is used. When created, a sealed class can’t be derived. However, a sealed method can’t be overridden when created. Structs can’t be inherited, because they are implicitly sealed.

C# Sealed class:

Any class can’t derive a sealed class in C# when created.

Example:

using System;  
sealed public class Flower{  
    public void color() { Console.WriteLine("White Flower!!"); }  
}  
public class Lily: Flower  
{  
    public void white() { Console.WriteLine("White Lily!!"); }  
}  
public class TestSealed  
{  
    public static void Main()  
    {  
        Lily f = new Lily();  
        f.color();  
        f.white(); 
    }  
}

Output:

Explanation:

In the above example, we are displaying the use and behavior of the sealed class in C#.

C# Sealed method:

A sealed method can’t be overridden further when created and is thus used with the override keyword in C#.

Example:

using System;  
public class Flower{  
    public virtual void color() { Console.WriteLine("...Rose"); }  
    public virtual void symbol() { Console.WriteLine("Symbolizes..."); }  
 
}  
public class RedRose: Flower  
{  
    public override void color() { Console.WriteLine("Red Rose!!"); }  
    public sealed override void symbol() {   
    Console.WriteLine("Symbolizes Love");   
    }  
}  
public class YellowRose : RedRose  
{  
    public override void color() { Console.WriteLine("Yellow Rose!!"); }  
    public override void symbol() { Console.WriteLine("Symbolizes Friendship!!"); }  
}  
public class TestSealed  
{  
    public static void Main()  
    {  
        YellowRose y = new YellowRose();  
        y.color();  
        y.symbol();  
    }  
}

Output:

Explanation:

In the above example, we are displaying the use and behavior of the sealed method in C#.

Local variables:

In C# local variables can’t be sealed.

Example:

using System;  
public class TestSealed  
{  
    public static void Main()  
    {  
        sealed float i = 2.5;  
        i--;  
        Console.WriteLine(i);  
    }  
}

Output:

Explanation:

In the above example, we are displaying the effect of the sealed keyword on the local variables in C#. It is not possible to seal the local variables in C# and hence an error will be generated.

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