Return a function from a function in Go (Golang)

In Golang function are first-order variables meaning that

They can be assigned to a variable

Passed around as function argument

Returned from a function

While returning a function from another function, the exact signature of the function has to be specified return list. As in below example

The return type of getAreaFunc function is func(int, int) int

func getAreaFunc() func(int, int)

getAreaFunc function hence it can return a function of type func(int, int) int

Code:

package main

import "fmt"

func main() {
    areaF := getAreaFunc()
    res := areaF(2, 4)
    fmt.Println(res)
}

func getAreaFunc() func(int, int) int {
    return func(x, y int) int {
        return x * y
    }
}

Output: