Name
IComparable
Synopsis
This interface is implemented by classes that can be ordered in a list.
Classes such as String
and
Int32
implement this interface. You can also
implement it in your own classes to create a type-specific method that
allows your objects to be sorted in arrays. This interface does not
allow classes to be compared with the greater-than and less-than
operators; that requires operator overloading. This interface simply
provides a well-known protocol for doing comparisons of objects. (Of
course, nothing prevents a C# programmer from defining overloaded
comparison operations and calling CompareTo()
as the implementation.)
To implement IComparable
, override the
CompareTo()
method. This method
accepts another instance of your IComparable
object and returns an integer that indicates the result of the
comparison. (Zero means equal, less than zero indicates that the
supplied object is less than the current instance, and greater than zero
indicates that the object is greater than the current instance). Note
that the actual value of the integer is irrelevant other than its
positive, negative, or zero status (similar to the way strcmp
works in C). Also note that because CompareTo()
accepts
an argument of IComparable
type, care must be taken
to ensure that it is a legitimate comparison — myInt.CompareTo(myString)
throws an ArgumentException
, for example.
public interface IComparable { // Public Instance Methods public method int CompareTo(object obj); }
Implemented By
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