Variables

Variables Go Specification

Variables in Go can be declared and initialized in several different ways.

Declare variable with var keyword

var pizza string
pizza = "pizza"

Alternatively you can write the statement like this

var pizza string = "pizza"

Notice that we didn't specify a type of string it was inferred

Inside functions, loops, and control flow statements you can use a shorthand operator

func printName(name string) string {
    modName := name + "is a person"
    return modName
}

You cannot use the shorthand operator := outside of this context

package main

import (
    "fmt"
)

str := "Hello, playground"

func main() {
    fmt.Println(str)
}

If you were to try to run this hello world program you would see the following error message syntax error: non-declaration statement outside function body

Naming variables

• Names must start with a letter and may contain letters, numbers or the _ (underscore) symbol

Default values

Variables are given default values when they are declared

var num int // 0

var dec float64 // 0

var str string // ""

var isVal bool // false

var num2 *int // nil

type Data struct{} // nil

func someFunc() {} // nil

Variables Playground