GeezerVison

In Go, variables are explicitly declared and used by the compiler to e.g. check type-correctness of function calls.

package main

import "fmt"

func main() {

var declares 1 or more variables.

    var a = "initial"
    fmt.Println(a)

You can declare multiple variables at once.

    var b, c int = 1, 2
    fmt.Println(b, c)

Go will infer the type of initialized variables.

    var d = true
    fmt.Println(d)

Variables declared without a corresponding initialization are zero-valued. For example, the zero value for an int is 0.

    var e int
    fmt.Println(e)

The := syntax is shorthand for declaring and initializing a variable, e.g. for var f string = "apple" in this case. This syntax is only available inside functions.

    f := "apple"
    fmt.Println(f)
}

$ go run variables.go
initial
1 2
true
0
apple