The **`complex`** function in Golang is a built-in function that constructs a complex value from two floating-point values.

The floating-point values represent the real and imaginary parts of the complex value. To use the `complex` function, you must ensure that both floating-point values are of the same size, i.e., they are both either `float32` objects or `float64` objects.

The process is illustrated below:

The prototype of the `complex` function is shown below:

```Go
func complex(r, i FloatType) ComplexType
```

# Parameters

The `complex` function takes the following two `FloatType` objects as parameters:

* **`r`**: The real part of the complex value.
* **`i`**: The imaginary part of the complex value.

# Return value

The `complex` function returns a `ComplexType` object that represents a complex value constructed from the provided parameters for the real and imaginary values.

If the parameters `r` and `i` are `float32` objects, then the `complex` function returns a `complex64` object; otherwise, if `r` and `i` are `float64` objects, then the `complex` function returns a `complex128` object.

# Example

The code below shows how the `complex` function works in Golang:

package main

import (
	"fmt"
)

func main() {

  // initializing complex values
	a := complex(5, 2)
	b := complex (10, 4)
	
  // printing complex values
	fmt.Println("The complex value a is:", a)
	fmt.Println("The complex value b is:", b)
	
  // printing real and imaginary parts
	fmt.Println("The real part of a is", real(a), "and the imaginary part is", imag(a))
	fmt.Println("The real part of b is", real(b), "and the imaginary part is", imag(b))
	
}


# Explanation

The `complex` function in lines $10$ and $11$ initializes a complex object based on the values provided for the real and imaginary parts. The code then outputs the complex values constructed by the `complex` function in lines $14$ and $15$.

The `real` and `imag` functions in lines $18$ and $19$ extract the real and imaginary parts of a complex value, respectively.

What is the complex function in Golang?

The complex function in Go constructs complex values from two same-sized floating-point numbers, returning complex64 or complex128 types.