Go has become increasingly popular in recent years, especially in my local area. It has been consistently displacing other backend languages like Ruby, Python, C# and Java. Go is wanted for its simplicity, explicitness, speed, and low memory consumption. Many developers that are new to the language, or new to a language that can handle memory directly using pointers end up misusing those pointers. What Is a Pointer? A pointer is a variable that stores the address of a value, rather than the value itself. If you think of a computer's memory (RAM) as a JSON object, a pointer would be like the key, and a normal variable would be the value. { : } "pointer" "variableValue" Lets see one in action: main { name := setName(&name, )
	fmt.Println(name)
} { *ptr = newName
} package import "fmt" func main () // create a normal string variable "original" // pass in a pointer to the string variable using '&' "qvault" func setName (ptr * , newName ) string string // dereference the pointer so we can modify the value // and set the value to "qvault" This prints: qvault As you can see, because we have a pointer to the address of the variable we can modify its value, even within the scope of another function. If the value were not a pointer, this would not work: , main {
	name := setNameBroken(name, )
	fmt.Println(name)
} {
	ptr = newName
} package import "fmt" func main () "original" "qvault" func setNameBroken (ptr , newName ) string string prints: original Pointers can be useful, but in the same way that they are useful, they can be dangerous. For example, if we dereference a pointer that has no value, the program will panic. For this reason we always check if an error value is nil before trying to print it. Syntax 1. Creating a pointer: & newString := newStringPointer := &newString "" If you print that pointer you will see a memory address. main {
	newString := newStringPointer := &newString
	fmt.Println(newStringPointer)
} package import "fmt" func main () "" prints: 0xc00000e1e0 Which is the memory address of that variable in your machine. 2. Describing a pointer: * In a function signature or type definition, the * is used to designate that a value is a pointer. {
} func passPointer (pointer * ) string 3. Dereferencing a pointer: * It can be slightly confusing, but the * is used to describe a pointer and it is also used as an operator to dereference a pointer. {
	newStringVariable := *pointer } func derefPointer (pointer * ) string // newStringVariable is just a normal string When Should I Use a Pointer? There are probably many nuanced cases for when a pointer is a good idea, but I would guess that 95% of the time when you use a pointer, it should be for one the following reasons: 1. A function that mutates one of its parameters When I call a function that takes a pointer as an argument, I expect that my variable will be mutated. If you aren't mutating the variable in your function, then you probably shouldn't be using a pointer. 2. Better Performance If you have a string that contains an entire novel in memory it gets really expensive to copy that variable each time it is passed to a new function. It may be worthwhile to pass a pointer instead, which will save CPU and memory. This comes at the cost of readability however, so only make this optimization if you must. 3. Need a Nil Value Option Sometimes a function needs to know what something's value is, as well as if it exists or not. I usually use this when reading JSON to know if a field exists or not. For example, if a JSON object is: { : } ----> *name: "name" "qvault" "qvault" { : } ----------> *name: "name" "" "" ----------------------> * : {} name nil Thanks These are some rules of thumb for when to use pointers in your code. If you are unsure, and a normal value will work just fine, I would advise avoiding the pointer. Pointers are useful tools but can lead to nasty bugs or unreadable code quite easily. By Lane Wagner @wagslane Previously published at https://qvault.io/2019/09/25/the-proper-use-of-pointers-in-go-golang/

A Developer’s Github Profile is Just as Important as their Resume Itself

 A Few Words on VS Code

Learn to code on Boot.dev

Nominated for 2022 - HackerNoon Contributor of the Year - Algorithms

Nominated for 2022 - HackerNoon Contributor of the Year - Mathematics

Nominated for 2022 - HackerNoon Contributor of the Year - Cryptography

Nominated for Coding Guru of 2022

Nominated for 2022 - HackerNoon Contributor of the Year - Github

Nominated for 2022 - HackerNoon Contributor of the Year - Online Education

Nominated for 2022 - HackerNoon Contributor of the Year - Job Hunting

Nominated for Super Career Strategist of 2022

Too Long; Didn't Read

Make resilience your competitive advantage

How And When To Use Pointers in Go

How And When To Use Pointers in Go

About Author

Comments

TOPICS

THIS ARTICLE WAS FEATURED IN

Related Stories

Untitled Story

Every Developer Should Learn to Give Up Sooner

104 Stories To Learn About Go

The Noonification: How to Use React to Replace useEffect (12/31/2022)

3 Golang Pitfalls Every Developer Needs to Know

207 Stories To Learn About Golang

Every Developer Should Learn to Give Up Sooner

104 Stories To Learn About Go

The Noonification: How to Use React to Replace useEffect (12/31/2022)

3 Golang Pitfalls Every Developer Needs to Know

207 Stories To Learn About Golang

Light-Mode

Classic

Newspaper

Dark-Mode

Neon Noir

Minty

HN StartUps