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nonocast
nonocast
学习 Go (Part 3: 快速语法)
变量
- 常量:
const x int32 = 1 - 变量:
var a int32 = 1 - 隐式变量:
a := 1 - 类型: bool, byte, intX, floatX, rune, uintptr, string, array, struct, function, interface, map, slice, channel
- int: 这个和C一样, int/uint跟随目标平台，int8, int16, int32则是指定长度
- 显示类型转换:
int(x), byte(y)
package main
func main() {
message := "hello world"
println(message)
}
- 数组
package main
func main() {
// var numbers [3]int32 = [3]int32{7, 8, 9}
numbers := [3]int32{7, 8, 9}
for i, n := range numbers {
println(i, ":", n)
}
}
逻辑
if
package main
func main() {
flag := true
if flag {
println("flag is on")
} else {
println("flag is off")
}
}
for
package main
func main() {
for i := 0; i < 5; i++ {
println(i)
}
}
注: 不支持++i
for..range
package main
func main() {
x := []int32{7, 8, 9}
for i, n := range x {
println(i, ":", n)
}
}
函数
func Add(x int, y int) int {
return x + y
}
指针
package main
func main() {
var x int32 = 7
var p *int32 = &x // p := &x
println(*p)
*p = 11
println(x)
}
结构
package main
type Book struct {
title string
author string
price float32
}
func main() {
book := Book{"title1", "author1", 19.9}
println(book.title)
}
goroutine
package main
import "time"
func foo() {
println("foo")
}
func main() {
go foo()
time.Sleep(1 * time.Second)
println("end")
}
到这里其实都非常C，在C的基础上很克制的增加了高级语法。你会很清晰的知道每个点对应C的什么痛点。
最后附上一个最简单的Gin的web app,
package main
import (
"net/http"
"github.com/gin-gonic/gin"
)
func main() {
r := gin.Default()
r.GET("/", func(c *gin.Context) {
c.String(http.StatusOK, "hello world")
})
r.GET("/ping", func(c *gin.Context) {
c.JSON(http.StatusOK, gin.H{
"message": "pong",
})
})
r.Run() // listen and serve on 0.0.0.0:8080 (for windows "localhost:8080")
}
go build能直接生成出单个可执行文件，没有那么多依赖，就这个比nodejs香太多了。。。
