Overloaded operators are functions with special name. The keyword operator is followed by the symbol for the operator being defined. Similar to any other function, an overloaded operator has a return type and a parameter list.

The following table shows which operators can be overloaded and which cannot −

Sr.No.Operators & Description
1+, -, !, ~, ++, --
These unary operators take one operand and can be overloaded.
2+, -, *, /, %
These binary operators take one operand and can be overloaded.
3==, !=, <, >, <=, >=
The comparison operators can be overloaded.
4&&, ||
The conditional logical operators cannot be overloaded directly.
5+=, -=, *=, /=, %=
The assignment operators cannot be overloaded.
6=, ., ?:, ->, new, is, sizeof, typeof

The overloaded operator is defined as −

public static Box operator+ (Box b, Box c) { }

## Example

The following is an example showing how to work with Operator Overloading in C# −

Live Demo

using System;

namespace OperatorOvlApplication {
class Box {
private double length; // Length of a box
private double height; // Height of a box

public double getVolume() {
return length * breadth * height;
}

public void setLength( double len ) {
length = len;
}

public void setBreadth( double bre ) {
}

public void setHeight( double hei ) {
height = hei;
}

public static Box operator+ (Box b, Box c) {
Box box = new Box();
box.length = b.length + c.length;
box.height = b.height + c.height;
return box;
}
}

class Tester {
static void Main(string[] args) {
Box Box1 = new Box(); // Declare Box1 of type Box
Box Box2 = new Box(); // Declare Box2 of type Box
Box Box3 = new Box(); // Declare Box3 of type Box
double volume = 0.0; // Store the volume of a box here

// box 1 specification
Box1.setLength(6.0);
Box1.setHeight(5.0);

// box 2 specification
Box2.setLength(12.0);
Box2.setHeight(10.0);

// volume of box 1
volume = Box1.getVolume();
Console.WriteLine("Volume of Box1 : {0}", volume);

// volume of box 2
volume = Box2.getVolume();
Console.WriteLine("Volume of Box2 : {0}", volume);

// Add two object as follows:
Box3 = Box1 + Box2;

// volume of box 3
volume = Box3.getVolume();
Console.WriteLine("Volume of Box3 : {0}", volume);
}
Volume of Box1 : 210
Volume of Box3 : 5400