Can anyone explain to me in JavaScript language what "pointers" are? -

Can anyone explain to me in JavaScript language what "pointers" are? -

i'm javascript coder who's learning go. i'm next tutorial: http://tour.golang.org/#52

package main import ( "fmt" "math" ) type vertex struct { x, y float64 } func (v *vertex) abs() float64 { homecoming math.sqrt(v.x*v.x + v.y*v.y) } func main() { v := &vertex{3, 4} fmt.println(v.abs()) }

i read in wikipedia , in go docs pointers are, still can understand them. can explain them me in javascript language?

they similar object references in js , other languages, not quite. pointer more powerful (and thus, more dangerous) references. consider next js code.

var = {foo: true}; var b = a; a.foo = false; console.log(b); // output: "object { foo: false }"

both a , b here pointer. when b = a don't clone object, create b refer (or point if will) same object a. in go can both:

type t struct { foo bool } := t{foo: true} b := a.foo = false fmt.println(b) // b copy, didn't change. prints "{true}". pa := &t{foo: true} pb := pa pa.foo = false fmt.println(pb) // pb points same struct pa, prints "&{false}"

playground

the of import difference in js can't replace object within function.

var = {foo: true}; (function(x) { x = {foo: false} })(a); console.log(a); // output: "object { foo: true }"

in go can fine:

pa := &t{foo: true} func(p *t) { *p = t{foo: false} }(pa) fmt.println(pa) // output: &{false}

playground

another difference can create pointers not structs, type, including pointers.

javascript pointers go