wiki/content/20200828180957-pointers.md

date	id	title
2020-08-28	f2e19e3e-e28a-4998-8b0c-38ebfdb559e5	Golang Pointers

Basics

Go also supports pointers. Default value is always NULL and you can't do pointer arithmetic. Other than that, nothing that will blow your mind here.

package main

import "fmt"

func main() {
    i, j := 42, 2701

    p := &i         // point to i
    fmt.Println(*p) // read i through the pointer
    *p = 21         // set i through the pointer
    fmt.Println(i)  // see the new value of i

    p = &j         // point to j
    *p = *p / 37   // divide j through the pointer
    fmt.Println(j) // see the new value of j
}

Pointers to Golang Structs

To facilitate lazy people like me Go allows you to lose the `*` when using a pointer to a struct

package main

import "fmt"

type Vertex struct {
    X int
    Y int
}

func main() {
    v := Vertex{1, 2}
    p := &v
    p.X = 123
    fmt.Println(v)
}