Sealed Class<\/b><\/p>\n
A sealed class cannot be used as a base class. Sealed classes are primarily used to prevent derivation. Because they can never be used as a base class, some run-time optimizations can make calling sealed class members slightly faster.<\/p>\n
<\/p>\n
We can also use the sealed modifier on a method or property that overrides a virtual method or property in a base class. This enables to allow classes to derive from class and prevent them from overriding specific virtual methods or properties.<\/p>\n
class X<\/p>\n
{<\/p>\n
protected\u00a0virtual\u00a0void F() { Console.WriteLine(“X.F”); }<\/p>\n
protected\u00a0virtual\u00a0void F2() { Console.WriteLine(“X.F2”); }<\/p>\n
}<\/p>\n
class Y : X<\/p>\n
{<\/p>\n
sealed\u00a0protected\u00a0override\u00a0void F() { Console.WriteLine(“Y.F”); }<\/p>\n
protected\u00a0override\u00a0void F2() { Console.WriteLine(“Y.F2”); }<\/p>\n
}<\/p>\n
class Z : Y<\/p>\n
{<\/p>\n
\/\/ Attempting to override F causes compiler error CS0239.<\/p>\n
\/\/ protected override void F() { Console.WriteLine(“C.F”); }<\/p>\n
<\/p>\n
\/\/ Overriding F2 is allowed.<\/p>\n
protected\u00a0override\u00a0void F2() { Console.WriteLine(“Z.F2”); }<\/p>\n
}<\/p>\n
It is an error to use the abstract<\/a> modifier with a sealed class, because an abstract class must be inherited by a class that provides an implementation of the abstract methods or properties.<\/p>\n When applied to a method or property, the sealed modifier must always be used with override<\/a>.<\/p>\n Because structs are implicitly sealed, they cannot be inherited.<\/p>\n Static Class<\/b><\/p>\n A class can be declared static, indicating that it contains only static members. It is not possible to create instances of a static class using the new keyword. Static classes are loaded automatically by the .NET Framework common language runtime (CLR) when the program or namespace containing the class is loaded.<\/p>\n <\/p>\n Difference between static and sealed class.<\/b><\/p>\n Sealed classes: <\/b><\/p>\n 1)Can create instances, but cannot inherit<\/p>\n 2)Can contain static as well as nonstatic members.<\/p>\n <\/p>\n Static classes:<\/b><\/p>\n 1)Can neither create their instances, nor inherit them<\/p>\n 2)Can have static members only.<\/p>\n \u00a0Difference between abstract and sealed<\/strong><\/p>\n The abstract<\/a> keyword enables to create classes and class<\/a> members that are incomplete and must be implemented in a derived class.<\/p>\n The sealed<\/a> keyword enables to prevent the inheritance of a class or certain class members that were previously marked virtual<\/a>.<\/p>\n class Animal<\/p>\n {<\/p>\n public void Eat() { Console.WriteLine(“Eating.”); }<\/p>\n public override string ToString()<\/p>\n {<\/p>\n return “I am an animal.”;<\/p>\n }<\/p>\n }<\/p>\n sealed class fr:Animal<\/p>\n {<\/p>\n public static void hj(int h) { h = 5; }<\/p>\n }<\/p>\n <\/p>\n static class fr1:Animal—–Error<\/strong><\/p>\n {<\/p>\n public static void hj(int h) { h = 5; }<\/p>\n }<\/p>\n","protected":false},"excerpt":{"rendered":" Sealed Class A sealed class cannot be used as a base class. Sealed classes are primarily used to prevent derivation. Because they can never be used as a base class, some run-time optimizations can make calling sealed class members slightly faster. We can also use the sealed modifier on a method or property that overrides a virtual method or… Read more →<\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3,11],"tags":[],"class_list":["post-173","post","type-post","status-publish","format-standard","hentry","category-c-vb","category-oop","xfolkentry"],"_links":{"self":[{"href":"http:\/\/mairwa.com\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/173","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/mairwa.com\/wordpress\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/mairwa.com\/wordpress\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/mairwa.com\/wordpress\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"http:\/\/mairwa.com\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=173"}],"version-history":[{"count":0,"href":"http:\/\/mairwa.com\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/173\/revisions"}],"wp:attachment":[{"href":"http:\/\/mairwa.com\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=173"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/mairwa.com\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=173"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/mairwa.com\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=173"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}