Say Hello World with Golang

• We will start with the traditional "Hello World" program which will appear in 1978 in the C programming language.
• C language influenced directly on Go.

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

• We assume that you have programmed in one or more languages whether compiled like c, c++, java or interpreted python, ruby, javascript.
• Go is compiled language.
• The Go toolchain converts source code. These toolchain accessed by a single command called go and multiple subcommands (run, build).
• $ go run hello_world.go
• prints -
• Hello World, 世界
• Go handles Unicode. so it can process text in all languages.
• If the program is more than a one-shot experiment means we run a file any time without processing used build subcommand.
• $ go build hello_world.go
• This creates an executable binary file called hello. that file can run anywhere without further processing 
• $ ./hello_world
• Hello World, 世界
• Let's talk about the program :
• Packages: Go code is organized into packages modules which are similar to libraries and modules in other languages.
• Go packages consists of one or more .go source file in a single directory
• Each source file begins with package declaration( package main) and another package which is followed by a file import.
• package main is special. it defined a standalone executable program, not a library

Gofmt :

• Gofmt is a tool that automatically formats go source code.

Usage : 

gofmt [flags] [path ...]

Why Gofmt :

1. Easier to write: never worry about minor formatting concern while hacking away,
2. Easier to read: when all code looks the same you need not mentally convert others formatting style into something you can understand.
3. Easier to maintain: mechanical changes to the source don't cause unrelated changes to the file's formatting; diffs show only the real changes.
4. uncontroversial: never have a debate about spacing or braces ever again!

Note :
On the survey of Go package Found that about 70% of them are formatted according to gofmt's rules.
This was more than expected.
To format your code, you can use the gofmt tool directly :
   - $gofmt -w hello_world.go

Command Line Arguments

Command line arguments is a parameter supplied to the program when it is involved.

Reference :

1. https://blog.golang.org/
2. https://tour.golang.org/welcome/1