Variables & inferred typing

This lesson discusses the basics of variable declaration, initialization and inferred typing.

We'll cover the following

Go is often referred to as a “simple” programming language, a language that can be learned in a few hours if you are familiar with any basic programming language. Go was designed to feel familiar and to stay as simple as possible, the entire language specification fits in just a few pages.

There are a few concepts we are going to explore before writing our first application.

Variables Declaration

The var statement declares a list of variables. The name of the variable comes first, ​and the type of variable is declared after it.

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var (
	name     string
	age      int
	location string
)

Or even

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var (
	name, location  string
	age             int
)

Variables can also be declared one by one:

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var name     string
var age      int
var location string

Variable Initialization

A var declaration can include initializers, one per variable.

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var (
	name     string = "Prince Oberyn"
	age      int    =  32
	location string = "Dorne"
)

If an initializer is present, the type can be omitted, the variable will take the type of the initializer (inferred typing).

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var (
	name     = "Prince Oberyn"
	age      =  32
	location = "Dorne"
)

You can also initialize multiple variables at once.

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var (
	name, location, age = "Prince Oberyn", "Dorne", 32
)

Inside a function, the := short assignment statement can be used in place of a var declaration with implicit type.

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package main
import "fmt"
func main() {
	name, location := "Prince Oberyn", "Dorne"
	age := 32
	fmt.Printf("%s age %d from %s ", name, age, location)
}

A variable can contain any type, including functions:

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func main() {
	action := func() { //action is a variable that contains a function
		//doing something
	}
	action()
}

Outside a function, every construct begins with a keyword (var, func and so on) and the := construct is not available.

Use Go’s declaration Syntax to read more about the Go syntax.

Let’s take a look at how constants are declared ​​in the next chapter.