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Sunday, 7 July 2013

Partial Class in C# with example, What is the use of partial class (Oops Programming)

Usage of Partial Class in Object Oriented Programming


In my previous articles we saw the oops programming concepts like Access Modifiers in C#,what is the use of Abstract Classes,Why we need sealed classes,Static Classes and Static Class Members in C# and various articles on WPF and Asp.Net.

           Now in this tutorial we will see what is partial class in C#, why use of partial class,difference between partial class and class in C#.


What is partial Class in C#? Difference between partial class and class?

In Object Oriented Programming it is possible to split the definition of a class or a struct, or an interface over two or more source files.Each source file contains a section of the class definition, and all parts are combined when the application is compiled. So a partial class is one which looks like a class except it is defined in multiple files. To Split a class definition , use partial keyword modifier.

Why we use partial classes:

  • This feature allows us to write single class file into multiple files so that multiple programmers can work at a time.
  • When working with automatically generated source, code can be added to class without having to recreate the source file.

Partial Class in C# with example:

 Take a class and name it as part1.cs in your console application project and write below.

Take another class and name it part2.cs and write below code.

To test these two classes take another class and name it as testpart.cs and write below code .

Key Points while writing Partial Classes in C#:

  • All the parts of the class must be defined within the namespace( same assembly or same module).
  • All the parts must be used with partial keyword.
  • All the parts must be available at compile time to form the final class.
  • All the parts must have the same accessibility level, such as public, private,protected
    and so on.
  • if any part of the class is declared as abstract then whole type is considered as abstract in the same
    manner for the sealed.
  • If any part is declares a base type, then the whole type inherits that class.
  • partial modifier is not available on delegate or enumeration declarations.


I hope you got an idea on how to and when to use partial classes with example and what precaution we should take care while writing partial classes. I would love to take feedback from my readers about my this writing.

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  1. Thanks Sekhar Babu for sharing valuable information with micro details.
    Awsome Keep it up :)

  2. Thanks Sekhar Babu for sharing valuable information with micro details.
    Awsome Keep it up :)

  3. very informative. Thanks

    please have a look at this link also

  4. good one!!
    very neatly explained,
    it may also help u:


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