Operator overloading allows redefining the behavior of operators for user-defined types. It is done by declaring special functions. There are two main types - unary operator overloading, which can redefine ++ and -- operators, and binary operator overloading, where at least one operand must be of the enclosing type. Common binary operators that can be overloaded include arithmetic, comparison, and bitwise operators. Overloading ensures operators have the same natural meaning for user-defined types as they do for built-in types.

1. Operator Overloading
In
C#
Presented By:
Charndeep
Kaur
Lovepreet kaur
Harpreet Kaur

2. Content
 What is Overloading?
 Types of Overloading.
 Operator Overloading.
 Types of Operator Overloading.
 References

3. What is Overloading?
 Multiple functions, Same Name ,
Different types or amount of Parameters.
 Two Type is:-
1. Method Overloading
2. Operator Overloading.

4. Operator Overloading
 “is a way of redefining the meaning of C#
operators”.
 Done with special functions.
 Can be Friend or Member Function.

5. Rules for Operator Overloading
 Only Predefined Operator is Overloaded.
 Cannot Change Operator Template.
 Natural meaning and overloaded meaning
is same.
 Must have a user defined operand.

6. Types of Operator
Overloading.
 Unary Operator Overloading.
 Binary Operator Overloading.

7. Overloadable Operator Not Overloadable Operator
Category Operators Category Operators
Binary Arithmetic + * / - % Conditional && ||
Unary Arithmetic + - ++ -- Operators += -= *=
Binary Bitwise & | ^ << >> Compound /= %=
Unary Bitwise ! ~ true false assignment [] () ?:
Logical Operators == != >= < <== new
> Other operators sizeof

8. Operator Overloading……
 Syntax
modifiers type operator op(arglist)
{
Method body//task defined
}

9. Unary Operator Overloading
• You can declare your own version of the
increment (++) and decrement (--) operators.
• They must be public, static and unary.
• They can be used in prefix and postfix forms
Example:

10. Binary Operator Overloading
 At least one parameter must be of the
enclosing type.
 You may overload as many times as you
like with different parameter types.
 You may return any type.
 No “ref” or “out” parameters.
 Two Types:-
1. Binary Arithmetic Operators
2. Binary Comparison Operators

11. Binary Arithmetic Operators
 Operators + - * / % ^ & | << >>
 One of the parameters must be of the enclosing type
// Class1 + Class1
public static Class1 operator+(Class1 lhs, Class1 rhs)
{
return new Class1(lhs.X + rhs.X);
}
// Class1 + int
public static Class1 operator+(Class1 lhs, int rhs)
{
return new Class1(lhs.X + rhs.X);
}
// int + Class1
public static Class1 operator+(int lhs, Class1 rhs)
{
return rhs + lhs;
}
Example

12. Binary Comparison Operators
 Operators == != < <= > >=
 Should return bool.
 Must overload them in „PAIRS‟
public static bool operator <(Class2 lhs, Class2 rhs)
{
return new Class2(lhs.i < rhs.i);
}
Example

13. Determining Equality
 Two kinds of comparison for objects:
 Identity and equality
 System.Object.Equals method
 Equality operator(==)
public override bool Equals(Object obj)
{
if (obj == null || GetType() != obj.GetType())
return false;
}

14. References
 http://devhawk.net/2003/07/09/operator-overloading-in-c/
 http://www.codeproject.com/KB/dotnet/vbnet_c__difference.aspx
 http://www.csharpcorner.com/UploadFile/prasadh/OperatorOverloading111
42005003229AM/OperatorOverloading.aspx
 http://www.vijaymukhi.com/documents/books/csbasics/chap12.htm
 http://blogs.msdn.com/b/ericlippert/archive/2007/05/14/why-are-
overloaded-operators-always-static-in-c.aspx