Golang returning functions

Question

Can anyone explain why 0's and 1's are printed and not anything else? Thank you!

func makeFunction(name string) func() {
    fmt.Println("00000")
    return func() {
        makeFunction2("abcef")
    }
}

func makeFunction2(name string) func() {
    fmt.Println("11111")
    return func() {
        makeFunction3("safsf")
    }
}

func makeFunction3(name string) func() {
    fmt.Println("33333")
    return func() {
        fmt.Printf("444444")
    }
}

func main() {
    f := makeFunction("hellooo")
    f()
}

Can anyone explain why 0's and 1's are printed and not anything else? Thank you!

Answer 1

To prints the 3's, you have to call twice:

f()()

And to prints the 4's too, just do:

f()()()

Because ...

// prints "00000" and returns a function that if run
// will invoked `makeFunction2`
f := makeFunction("hello")

// `makeFunction2` is called, printing "11111" and returns 
// a function that if run will invoked `makeFunction3`
f1 := f()

// `makeFunction3` is called, printing "33333" and returns
// a function that if run will invoked `makeFunction4`
f2 := f1()

Test question, what does it print out if you do this?

f := makeFunction("Hello")()()
f()

This is known as currying or closure, but in your example you have not closed over any local value so the latter loses its meaning.