Summary of pointer of Golang

#go

Sometimes I confuse how to retrieve from pointer variable. So I wanna summary the pointer of Golang not to forget them.
Because I haven't used languages which have pointer variable.

Then it's just memo for me.

& stands for the memory address of value.
* (in front of values) stands for the pointer's underlying value
* (in front of types name) stands for to store an address of another variable

It's an example

package main

import "fmt"

type H struct {
    id *int
}

func main() {
    a := 10

    p := &a
    fmt.Println(p)  //0x10410020
    fmt.Println(*p) //10

    a = 11
    fmt.Println(p)  //0x10410020
    fmt.Println(*p)

    q := 90
    b := H{id: &q}
    fmt.Println(b.id)   //0x1041002c
    fmt.Println(*b.id)  //90

    q = 80
    fmt.Println(b.id)   //0x1041002c
    fmt.Println(*b.id)  //80
}

Top comments (4)

Alex Pliutau • Nov 30 '17

Another way to get a pointer is to use the built-in new function:

func one(xPtr *int) {
  *xPtr = 1
}
func main() {
  xPtr := new(int)
  one(xPtr)
  fmt.Println(*xPtr) // x is 1
}

new takes a type as an argument, allocates enough memory to fit a value of that type and returns a pointer to it.

sirbowen78 • Nov 9 '20

Concise and easy to understand summary, thank you for sharing :)

田浩 • Nov 28 '17

play.golang.org/p/YI6-As7AhZ

Nana Yeboah • Nov 10 '18

Thank you so much my friend. This is exactly what I needed.

DEV Community

Summary of pointer of Golang

Top comments (4)

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