Operator Overloading In C#

In this blog, you will learn about the operators in C# and why and how to overload the operators.

What is operator?

Operators are the symbols, which are used to perform an operation between the operands. As,

 

a + b 

Operands : a and b

Operator : +

 

Type of operators:

 

Operators are of two types, which are:

 

Unary Operators : ++, --, -

 

Binary Operators : +, -, *, /, >, <, =, == etc.

 

Why operator overloading is required? 

 

Usually, the operators work with the pre-defind type like int, float, string etc. If you want to perform an operation on the user defined type (object), it is required to re-define the operators (overload) to perform the operation.  

Number n1=new Number(10,20);
Number n2=new Number(5,10);
Number n3=n1+n2;

n1 and n2 are two user defined types (object) and + operator is required to perform an addition between the two objects. This is only possible with the operator overloading.

 

Example:

 

Create a class to define a user defined type (object). 

 class Numbers
 {
        public int num1, num2;
        public Numbers()
        {
            num1 = 0;
            num2 = 0;
        }
        public Numbers(int a,int b)
        {
            num1 = a;
            num2 = b;
        }
        public void PrintNumbers()
        {
            Console.WriteLine("Num1 :"+num1);
            Console.WriteLine("Num2 :" + num2);
        }
}

Write the code to redefine the operators (overload) to perform a user defined operation.

 

Operator overloading : + 

public static Numbers operator +(Numbers ob1, Numbers ob2)
{
            Numbers ob3 = new Numbers();
            ob3.num1 = ob1.num1 + ob2.num1;
            ob3.num2 = ob1.num2 + ob2.num2;
            return ob3;
}

Operator overloading : ++ 

public static Numbers operator ++(Numbers ob1)
{
            Numbers ob2 = new Numbers ();
            ob2.num1 = ob1.num1 + 1;
            ob2.num2 = ob1.num2 + 1;
            return ob2;
}

Operator overloading : > 

public static bool operator >(Numbers ob1, Numbers ob2)
        {
            if (ob1.num1 > ob2.num1 && ob1.num2 > ob2.num2)
            {
                return true;
            }
            else
            {
                return false;
            }
}

Operator overloading : <

public static bool operator <(Numbers ob1, Numbers ob2)
{
            if (ob1.num1 < ob2.num1 && ob1.num2 < ob2.num2)
            {
                return true;
            }
            else
            {
                return false;
            }
}

Write the statement in Main method to test the Application.

 

Statement 1 - To test + operator overloading.

Numbers n1 = new Numbers();
Numbers n2 = new Numbers(10,20);
Numbers n3 = new Numbers(20,30);
n1 = n2 + n3;
n1.PrintNumbers();

Statement 2 - To test ++ operator overloading.

Numbers n1 = new Numbers();
Numbers n2 = new Numbers(10,20);
//Pre increment
n1 = ++n2;
n1.PrintNumbers();
n2.PrintNumbers();

//Post increment
n1 = n2++;
n1.PrintNumbers();
n2.PrintNumbers();

Statement 3 - To test >operator overloading.

Numbers n1 = new Numbers(10,20);
Numbers n2 = new Numbers(20,30);
if (n1 > n2)
{
    Console.WriteLine("True");
}
else
{
    Console.WriteLine("False");
}

Statement 4 - To test < operator overloading. 

Numbers n1 = new Numbers(10,20);
Numbers n2 = new Numbers(20,30);
if (n1 < n2)
{
    Console.WriteLine("True");
}
else
{
    Console.WriteLine("False");
}

Note

Some of the operators are not overloaded. As- =, ?:,->, sizeof, new etc.The comparison operators must be overloaded in the pairs.

 

That's all. Thank you. If any suggestion or clarification is required, kindly revert back with the comments.