Go Overview & Environment Setup

Why Go Exists

Google created Go in 2009 to solve three pain points: slow C++/Java compiles, unwieldy dependency management, and the complexity of concurrent programming. Go compiles to a single static binary, has a tiny keyword set (25), garbage collection, and goroutines that make concurrency a language-level feature rather than a library afterthought.

Cloud-native pedigree: Docker, Kubernetes, Terraform, etcd are all written in Go.
Fast compilation: large projects build in seconds.
Simple concurrency: goroutines and channels are built into the language.

Installing the Toolchain

# 下载安装包（go.dev/dl）后验证
go version       # go1.23+

# Linux 包管理器
sudo apt install golang-go

# 环境变量（默认即可，需要自定义时再改）
go env GOPATH
go env GOMODCACHE

Modern Go is module-based: every project has a go.mod and lives anywhere on disk. GOPATH mode is only for very old code.

First Program

mkdir hello && cd hello
go mod init example.com/hello   # 生成 go.mod
go get github.com/gin-gonic/gin # 添加依赖
go build                         # 编译为当前平台二进制
go run .                         # 直接运行

package main

import "fmt"

func main() {
    fmt.Println("Hello, BackendWiki!")
}

main package + func main is the entry point.
Unreferenced imports are a compile error — keep imports tidy.
gofmt / gofmt -w formats code; there is one canonical style, no formatting debates.

Go 为什么诞生

Google 于 2009 年创造 Go，直指三大痛点：C++/Java 编译慢、依赖管理臃肿、并发编程复杂。Go 编译出单一静态二进制，关键字只有 25 个，自带垃圾回收，goroutine 把并发做成了语言级特性而非库的补丁。

云原生血统：Docker、Kubernetes、Terraform、etcd 全部用 Go 编写。
编译飞快：大型项目秒级构建。
简洁并发：goroutine 与 channel 是语言原生支持。

安装工具链

# 下载安装包（go.dev/dl）后验证
go version       # go1.23+

# Linux 包管理器
sudo apt install golang-go

# 环境变量（默认即可，需要自定义时再改）
go env GOPATH
go env GOMODCACHE

现代 Go 是 module 模式：每个项目有 go.mod，可以放在磁盘任意位置。GOPATH 模式只用于非常老的代码。

第一个程序

mkdir hello && cd hello
go mod init example.com/hello   # 生成 go.mod
go get github.com/gin-gonic/gin # 添加依赖
go build                         # 编译为当前平台二进制
go run .                         # 直接运行

package main

import "fmt"

func main() {
    fmt.Println("Hello, BackendWiki!")
}

main 包 + func main 是程序入口。
未使用的 import 会编译报错，保持 import 整洁。
gofmt / gofmt -w 统一格式化，全社区只有一种代码风格。