# C++ real() function with examples

In this article, we will be learning C++ – real() function with examples. The real() function in C++ is defined header file “complex.h”. It comes handy when we need to find the real part of a complex number. It takes a parameter that holds the complex number and returns the real part of the complex number.

At first, let us see how a complex number looks like. A complex number has two parts – the real part and the imaginary part. The imaginary part is preceded by ‘i’ and has a form of a+ib where a is the real part and b is the imaginary part. Few examples are:-

1. 5 + 7i
2. 0 + 5i

Syntax:- template< class T >
constexpr T real( const std::complex<T>& z );

here z is the parameter which holds the complex number.

## real() function and examples

1. In the below program, we will find the real part of the complex number 7 + 9i with the real() function.
```#include <bits/stdc++.h>
using namespace std;
int main()
{
complex<double> comp(7, 9);  //declaring comp with 7+9i
cout << "Complex number with imaginary part: " << comp << endl;  //prints the complete complex number
cout << "Real part: " << real(comp) << endl;  //prints the real part of the complex number
return 0;
}```

The code generates the following output:-

```Complex number with imaginary part: (7,9)
Real part: 7

--------------------------------
Process exited after 0.05535 seconds with return value 0
Press any key to continue . . .
```
2. In the below program, we will find the real part of the complex number 0+i with real() function.
```#include <bits/stdc++.h>
using namespace std;
int main()
{
complex<double> comp( 0, 1);  //declaring comp with 0+i
cout << "Complex number with imaginary part: " << comp << endl;  //prints the complete complex number
cout << "Real part: " << real(comp) << endl;  //prints the real part of the complex number
return 0;
}```

The code generates the following output:-

```Complex number with imaginary part: (0,1)
Real part: 0

--------------------------------
Process exited after 0.06017 seconds with return value 0
Press any key to continue . . .
```