C# 0 The Complete Reference

Implementing IComparable for Generic Collections

If you want to sort objects that are stored in a generic collection, then you will implement 

IComparable

. This version defines the generic form of 

CompareTo( )

 shown here:

int CompareTo(T 

obj)

CompareTo( )

 compares the invoking object to 

obj.

 To sort in ascending order, your 

implementation must return zero if the objects are equal, a positive value if the invoking 

object is greater than 

obj,

 and a negative value if the invoking object is less than 

obj.

 To 

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sort in descending order, reverse the outcome of the comparison. When implementing 

IComparable

, you will usually pass the type name of the implementing class as a type 

argument.

The following example reworks the preceding program so that it uses