# Java Program to Add Two Complex Numbers

Complex numbers have two parts – real part and imaginary part. In this tutorial, we will write a Java program to add two complex numbers. When adding complex numbers we add real parts together and imaginary parts together as shown in the following diagram.

## Example – Adding two complex numbers in Java

In this program we have a class `ComplexNumber`. In this class we have two instance variables `real` and `img` to hold the real and imaginary parts of complex numbers.

We have declared a method sum() to add the two numbers by adding their real and imaginary parts together.

The constructor of this class is used for initializing the complex numbers. For e.g. when we create an instance of this class like this `ComplexNumber temp = new ComplexNumber(0, 0);`, it actually creates a complex number `0 + 0i`.

```public class ComplexNumber{
//for real and imaginary parts of complex numbers
double real, img;

//constructor to initialize the complex number
ComplexNumber(double r, double i){
this.real = r;
this.img = i;
}

public static ComplexNumber sum(ComplexNumber c1, ComplexNumber c2)
{
//creating a temporary complex number to hold the sum of two numbers
ComplexNumber temp = new ComplexNumber(0, 0);

temp.real = c1.real + c2.real;
temp.img = c1.img + c2.img;

//returning the output complex number
return temp;
}
public static void main(String args[]) {
ComplexNumber c1 = new ComplexNumber(5.5, 4);
ComplexNumber c2 = new ComplexNumber(1.2, 3.5);
ComplexNumber temp = sum(c1, c2);
System.out.printf("Sum is: "+ temp.real+" + "+ temp.img +"i");
}
}```

Output:

`Sum is: 6.7 + 7.5i`