Ruby Programmer's Golang Tour 01

This is a creation in Article, where the information may have evolved or changed.

Golang's import @ Ruby's require

We're just taking this opportunity to review Ruby's require first.

require(name) → true or false

Require loads the specified file, returns True if the load succeeds, or false if it has already been loaded.

require 'csv'=> truerequire 'csv'=> false

If the filename resolution is not an absolute path, it will be looked up in the directory listed $MY _ruby_home.

require 'foo'=>  cannot load such file -- foo    from /Users/jiyarong/.rvm/rubies/ruby-2.3.0/lib/ruby/site_ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'    from /Users/jiyarong/.rvm/rubies/ruby-2.3.0/lib/ruby/site_ruby/2.3.0/rubygems/core_ext/kernel_require.rb:55:in `require'    from (irb):3    from /Users/jiyarong/.rvm/rubies/ruby-2.3.0/bin/irb:11:in `<main>'

And look at the concept of Golang ' package '.

Each Go program is made up of packages.

The entry that the program runs is the package main .

package mainimport "fmt"func main() {    fmt.Println("Hello, 世界")}

After you have imported a package, you can call it with its exported name.
For example, after the import "fmt" , you can use fmt this prefix to invoke the FMT package inside the Println function, forced to use Ruby to explain the words, fmt presumably can be understood as a class bar, Println is a class method of this class

$ go run hello.go Hello, World!

You can also import multiple files at once

package mainimport (    "fmt"    "math")func main() {    fmt.Printf("Now you have %g problems.", math.Nextafter(2, 3))}

import (    "fmt"    "math")等同于import "fmt"import "math/rand"