In this example, you will learn to take two complex numbers as structures and add them by creating a user-defined function.

To understand this example, you should have the knowledge of the following C programming topics:

```
#include <stdio.h>
typedef struct complex {
float real;
float imag;
} complex;
complex add(complex n1, complex n2);
int main() {
complex n1, n2, result;
printf("For 1st complex number \n");
printf("Enter the real and imaginary parts: ");
scanf("%f %f", &n1.real, &n1.imag);
printf("\nFor 2nd complex number \n");
printf("Enter the real and imaginary parts: ");
scanf("%f %f", &n2.real, &n2.imag);
result = add(n1, n2);
printf("Sum = %.1f + %.1fi", result.real, result.imag);
return 0;
}
complex add(complex n1, complex n2) {
complex temp;
temp.real = n1.real + n2.real;
temp.imag = n1.imag + n2.imag;
return (temp);
}
```

**Output **

For 1st complex number Enter the real and imaginary parts: 2.1 -2.3 For 2nd complex number Enter the real and imaginary parts: 5.6 23.2 Sum = 7.7 + 20.9i

In this program, a structure named` complex`

is declared. It has
two members: `real` and `imag`. We then created two
variables `n1` and `n2` from this structure.

These two structure variables are passed to the `add()`

function.
The function computes the sum and returns the structure containing the sum.

Finally, the sum of complex numbers is printed from the
`main()`

function.