C# 0 The Complete Reference

int

,

string

, and 

double

. It 

is also easy to implement for classes that you create.

The

IComparable

 interface defines only the 

CompareTo( )

 method shown here:

int CompareTo(object 

obj

)

CompareTo( )

 compares the invoking object to 

obj.

 It returns zero if the two 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 use 

CompareTo( )

, you must specify a constraint that requires every type argument 

to implement the 

IComparable

 interface. Then, when you need to compare two instances of 

the type parameter, simply call 

CompareTo( )

. For example, here is a corrected version of 

IsIn( )

:

// Require IComparable interface.

public static bool IsIn(T what, T[] obs) where T : IComparable {

  foreach(T v in obs)

www.freepdf-books.com

---