Pointers in Go

External

• https://go.dev/ref/spec#Pointer_types

Internal

• Go Language

Overview

A pointer is a data type that represents a virtual address in memory. The pointer data type comes with two operators: & (the referencing operator), and * (the dereferencing operator).

A pointer can be declared as such:

var ip *int // a pointer to an int

The Referencing Operator &

The referencing operator (the ampersand operator) returns an address, also known as a "reference", from a variable. & should be read as "address of ...". It works with variables and also with literals. The syntax &user{name:"Bill"} where user is a struct is legal. The address is represented internally as an instance of type pointer. The address points to the location in memory where the instance associated with the "referenced" variable is stored.

&<variable-name>

color := "blue"
pointerToColor := &color
println(pointerToColor) // prints "0xc000058720"

The Dereferencing Operator *

The dereferencing operator (star operator) takes a pointer and returns the value in memory the pointer's address points toward. The variable must contain a pointer type instance, otherwise the code will not compile. The value thus exposed can be read or written.

*<pointer-name>

color := "blue"
pointerToColor := &color
println(*pointerToColor) // prints "blue"
*pointerToColor = "red"
println(color) // prints "red"