C# | Operator Overloading
Last Updated :
07 Aug, 2021
The concept of overloading a function can also be applied to operators. Operator overloading gives the ability to use the same operator to do various operations. It provides additional capabilities to C# operators when they are applied to user-defined data types. It enables to make user-defined implementations of various operations where one or both of the operands are of a user-defined class. Only the predefined set of C# operators can be overloaded. To make operations on a user-defined data type is not as simple as the operations on a built-in data type. To use operators with user-defined data types, they need to be overloaded according to a programmer’s requirement. An operator can be overloaded by defining a function to it. The function of the operator is declared by using the operator keyword.
Syntax :
access specifier className operator Operator_symbol (parameters)
{
// Code
}
Note : Operator overloading is basically the mechanism of providing a special meaning to an ideal C# operator w.r.t. a user-defined data type such as structures or classes.
The following table describes the overloading ability of the various operators available in C# :
Operators |
Description |
+, -, !, ~, ++, – – |
unary operators take one operand and can be overloaded. |
+, -, *, /, % |
Binary operators take two operands and can be overloaded. |
==, !=, = |
Comparison operators can be overloaded. |
&&, || |
Conditional logical operators cannot be overloaded directly |
+=, -+, *=, /=, %=, = |
Assignment operators cannot be overloaded. |
Overloading Unary Operators
The return type can be of any type except void for unary operators like !, ~, + and dot (.) but the return type must be the type of ‘Type’ for – and ++ operators and must be a bool type for true as well as false operators. But do remember that the true and false operators can be overloaded as pairs only. The compilation error arises if a class declares one of these operators without declaring the other.
The following syntax shows the use of Unary operator –
operator (object);
here, operator is a symbol that denotes a unary operator.
operator a;
Example :
Input : 15, -25
Output : -15, 25
Input : -22, 18
Output : 22, -18
C#
using System;
namespace Calculator {
class Calculator {
public int number1 , number2;
public Calculator( int num1 , int num2)
{
number1 = num1;
number2 = num2;
}
public static Calculator operator -(Calculator c1)
{
c1.number1 = -c1.number1;
c1.number2 = -c1.number2;
return c1;
}
public void Print()
{
Console.WriteLine ( "Number1 = " + number1);
Console.WriteLine ( "Number2 = " + number2);
}
}
class EntryPoint
{
static void Main(String []args)
{
Calculator calc = new Calculator(15, -25);
calc = -calc;
calc.Print();
}
}
}
|
Output :
Number1 = -15
Number2 = 25
Overloading Binary Operators
Binary Operators will work with two Operands. Examples of binary operators include the Arithmetic Operators (+, -, *, /, %), Arithmetic Assignment operators (+=, -+, *=, /+, %=) and Relational Operators etc. Overloading a binary operator is similar to overloading a unary operator, except that a binary operator requires an additional parameter.
Syntax :
operator operator (object1, object2);
Here, second "operator" is a symbol that
denotes a binary operator.
operator + (a, b);
Example :
Input : 200, 40
Output : 240
Input : 300, 20
Output : 320
C#
using System;
namespace BinaryOverload {
class Calculator {
public int number = 0;
public Calculator() {}
public Calculator( int n)
{
number = n;
}
public static Calculator operator + (Calculator Calc1,
Calculator Calc2)
{
Calculator Calc3 = new Calculator(0);
Calc3.number = Calc2.number + Calc1.number;
return Calc3;
}
public void display()
{
Console.WriteLine( "{0}" , number);
}
}
class CalNum {
static void Main( string [] args)
{
Calculator num1 = new Calculator(200);
Calculator num2 = new Calculator(40);
Calculator num3 = new Calculator();
num3 = num1 + num2;
num1.display();
num2.display();
num3.display();
}
}
}
|
Output :
200
40
240
Benefits of Operator Overloading :
- Operator Overloading provides additional capabilities to C# operators when they are applied to user-defined data types.
- Operators may be considered as functions internal to the compiler.
Share your thoughts in the comments
Please Login to comment...