var vs := in Go

Question

In the Go web server example here: http://golang.org/doc/effective_go.html#web_server

The following line of code works

var addr = flag.String(\"addr\         


        

Answer 1

In Go, top-level variable assignments must be prefixed with the var keyword. Omitting the var keyword is only allowed within blocks.

package main

var toplevel = "Hello world"         // var keyword is required

func F() {
        withinBlock := "Hello world" // var keyword is not required
}