C# 0 The Complete Reference

CompareTo( )

 is implemented by 

MyClass

:

public int CompareTo(object obj) {

  return Val - ((MyClass) obj).Val;

}

Because the parameter to 

CompareTo( )

 must be of type 

object

,

obj

 must be explicitly cast 

to

MyClass

 in order for 

Val

 to be accessed. However, it’s precisely this type of thing that 

generics were designed to eliminate!

To solve this problem, C# provides a generic version of 

IComparable

, which is declared 

like this:

public interface IComparable

In this version, the type of data being compared is passed as a type argument to 

T

. This 

causes the declaration of 

CompareTo( ) 

to be changed, as shown next:

int CompareTo(T 

obj

)

Now, the parameter to 

CompareTo( )

 can be specified as the proper type and no cast from 

object

 is needed. 

IComparable

 is also implemented by all built-in types.

Here is an improved version of 

MyClass

 that implements 

IComparable

:

// This version of MyClass implements IComparable

class MyClass : IComparable {

  public int Val;

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