Golang study notes 1: introduction

The main features of the Go language

 Automatic garbage collection 

 Richer built-in types 

 The function returns multiple values 

 Error handling 

 Anonymous functions and closures 

 Types and interfaces 

 Concurrent programming 

 reflection 

 Linguistic interactivity 
 A high performance / The efficient development 

The installation

Installation instructions address http: / / golang org/doc/install

Package download address https: / / code google. com p/go/downloads/list

Verify that the installation was successful

go version // Check the version 

Environment variable Settings

Overall directory structure

Through the package organization, only package named main can contain the main function

One program has only one main package

Import other non-main packages through the import keyword

bin/

    |- mathapp

pkg/

    |-  The platform of 

        |- xxx.a

src/

    |- mathapp

        |- main.go

Helloworld

package main // declaratory package
import {

    "fmt" //import  Package, can not contain unused packages, otherwise the compilation error 

}

func main() { // The entry function ,  No parameters, no return value 

    fmt.Println("hello world")

}
// run 

$go run hello.go
$go build hello.go

$./hello

go command

View from the command line

go help

go build  compile 

go clean  Removes the build build file from the current source package 

go fmt  Formatting code 

go get  Get the remote code package on the fly 

go install  Generate the results file and compile the good results 1 to $GOPATH/pkg or $GOPATH/bin

go test  Run the test executable 

go doc   godoc -http=:8080  To view the document 
go fix  Fix old version code to new version 

go version View current version 

go env  View the current go Environment variables 

go list  Lists all current installations package

go run  Compile and run go Language program 

debugging

Debugging with gdb, the go language is already built in

list

break

delete

backtrace

info

print

whatis

next

continue

set variable

Editor Settings

vim

Other supplementary
annotation

// A single 

/* ----- */  Multiple lines 

import multiple packages

import (

    "fmt"

    "os"

)

Call the ground function in the package

<packageName>.<Function>