A quick tour of Golang grammar

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

Key words

break      default       func     interface   selectcase       defer         go       map         structchan       else          goto     package     switchconst      fallthrough   if       range       typecontinue   for           import   return      var

Built constants:

true false iota nil

Built-in type:

int int8 int16 int32 int64uint uint8 uint16 uint32 uint64 uintptrfloat32 float64 complex128 complex64bool byte rune string error

Built-in functions:

make len cap new append copy close deletecomplex real imagpanic recover

Statement

var i = 1000func main() {}const PI = 3.141592653589793 type Model struct {}

Variable

var 名字 类型 = 表达式

Pointer

取地址 p := &x解引用 *p = 2

Some data types

Array

// 字面量array := [5]int{1,2,3,4,5}

Slice

Map

var myMap map[keyType]valueTypemake(map[keyType]valueType, 100)myMap = map[keyType]valueTyep {}

New

new(类型） 返回该类型的一个指针p := new(int)```go# 生命周期包级的变量和程序的生命周期一致局部变量不再被引用时自动销毁 # 流程控制## if else```gofunc example(x int) int {     if x == 0 {        return 5    } else {        return x }}

Switch case Default Fallthrough

switch i {    case 0:        fmt.Printf("0")     case 1:        fmt.Printf("1")     case 2:        fallthrough     case 3:        fmt.Printf("3")     case 4, 5, 6:        fmt.Printf("4, 5, 6")     default:        fmt.Printf("Default")}

For break continue

Normal for loop

sum := 0for i := 0; i < 10; i++ {    sum += i } a := []int{1, 2, 3, 4, 5, 6}for i, j := 0, len(a) – 1; i < j; i, j = i + 1, j – 1 {    a[i], a[j] = a[j], a[i]}

Imitate while (go without while, do-while)

sum := 0 for {    sum++    if sum > 100 {        break    } }

Break jump

for j := 0; j < 5; j++ {    for i := 0; i < 10; i++ {        if i > 5 {             break JLoop        }        fmt.Println(i)    } }JLoop: // ...

Goto

Interface

Interface Reader {
Read ()
}

Function

Defer func1 ()
Defer Func2 ()
Advanced after out, so first execute FUNC2, then execute func1

Goroutine

Start a goroutine (go concurrency)

go f()

Create a channel (communication mechanism for GO)

ch = make(chan int)ch = make(chan int, 3) // 带缓冲

Receive

x = <-ch // 从ch接收数据，并保存在x

Send

ch <- x // 将x的内容发送到ch

Shut down

close(ch)

Multiplexing

 select {case <-CH1://Case x: = <-CH2://FMT. PRINTLN (x) case CH3 <-y://default://}