CODEWITHSUNDEEP
pointersgostruct
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Reputation: 900

Why do you have to use an asterisk for pointers but not struct pointers?

I think I am missing a part of technical background. But I don't get, why I have to use an * to access the value of a simple pointer, but not for accessing values of a struct.

For example with a simple value:

func main() {
    i := 42
    p := &i
    *p = 21         // <<< I have to use an asterisk to access the value
    // ...
}

And a example with a struct:

type Vertex struct {
    X int
    Y int
}

func main() {
    v := Vertex{1, 2}
    p := &v
    p.X = 1e9       // <<< I do not have to use an asterisk
    // ...
}

(yes, the samples are from the official go lang tour here: https://go-tour-de.appspot.com/moretypes/4)

Just from my thoughts I would expect something like this

    *p.X = 1e9

or (yeah, this would be somewhat strange)

    p.*X = 1e9

So, why don't I have to use an asterisk to access struct pointer?

Upvotes: 2

Views: 659

Answers (1)

Amit Kumar Gupta
Amit Kumar Gupta

Reputation: 18567

The official Golang tour where you found that example [here] explicitly says:

To access the field X of a struct when we have the struct pointer p we could write (*p).X. However, that notation is cumbersome, so the language permits us instead to write just p.X, without the explicit dereference.

Upvotes: 6

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