|
Operator Overloading in C#
C# allows you to overload operators for use on your own classes. This makes it possible to define a user defined data type
and to use as a fundamental data type. For example, you might create a new data type called StringCompare to represent a string,
and provide methods that perform comparisions, such as using the == and != operators.
The following example demonstrates string comparision by overloading '==' and '!=' operators.
public class StringCompare
{
private string firstString;
private string secondString;
public StringCompare(string string1, string string2)
{
firstString = string1;
secondString = string2;
}
public static bool operator ==(StringCompare string1, StringCompare string2)
{
Console.WriteLine("In operator ==");
//
if ( (string1.firstString == string2.firstString) &&
(string1.secondString == string2.secondString))
{
return true;
}
return false;
}
public static bool operator !=(StringCompare string1, StringCompare string2)
{
Console.WriteLine("In operator !=");
//
if ( (string1.firstString == string2.firstString) &&
(string1.secondString == string2.secondString))
{
return false;
}
return true;
}
public override bool Equals(object o)
{
Console.WriteLine("In method Equals");
if (!(o is StringCompare))
{
return false;
}
return this == (StringCompare)o;
}
public override string ToString()
{
string s = firstString + " " + secondString;
return s;
}
public override int GetHashCode()
{
return base.GetHashCode();
}
}
class Program
{
static void Main(string[] args)
{
StringCompare s1 = new StringCompare("Pat", "Weaver");
Console.WriteLine("s1: {0}", s1.ToString());
StringCompare s2 = new StringCompare("Kathy", "Smith");
Console.WriteLine("s2: {0}", s2.ToString());
if (s1 == s2)
{
Console.WriteLine("s1: {0} == s2: {1}", s1.ToString(), s2.ToString());
}
else
{
Console.WriteLine(s1.ToString() + " is not same as " + s2.ToString());
}
if (s1 != s2)
{
Console.WriteLine(s1.ToString() + " is not same as " + s2.ToString());
}
}
}
|
Downloads
The sample code can be downloaded from below link. The code is complied with Microsoft Visual C# 2005.
|