24. June 2013 20:16
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Sumedh
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sealed Keyword
- The sealed modifier can be applied to classes, instance methods and properties.
- A sealed class cannot be inherited.
- A sealed method overrides a method in a base class, but itself cannot be overridden further in any derived class.
- When applied to a method or property, the sealed modifier must always be used with override.
Use the sealed modifier in a class declaration to prevent inheritance of the class, as in this example:
sealed class SealedClass
{
public int x;
public int y;
}
- It is an error to use a sealed class as a base class or to use the abstract modifier with a sealed class.
- Structs are implicitly sealed; therefore, they cannot be inherited.
Example
// cs_sealed_keyword.cs
using System;
sealed class SealedClass
{
public int x;
public int y;
}
class MainClass
{
static void Main()
{
SealedClass sc = new SealedClass();
sc.x = 110;
sc.y = 150;
Console.WriteLine("x = {0}, y = {1}", sc.x, sc.y);
}
}
Output :
x = 110, y = 150
In the preceding example, if you attempt to inherit from the sealed class by using a statement like this:
class MyDerivedC: SealedClass {} // Error
you will get the error message:
'MyDerivedC' cannot inherit from sealed class 'SealedClass'.
Reference
sealed (C# Reference)
a91864d6-5517-42e3-9cbd-60a2721038be|0|.0|96d5b379-7e1d-4dac-a6ba-1e50db561b04
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