SRE文档

深浅模式

https://haicoder.net/golang/golang-float.html

1.go语言常量 ​

常量，就是程序编译阶段就确定下来的值，而程序在运行时则无法改变该值。g在Go程序里，常量可以是数值类型（包括整型、浮点型和复数类型）、布尔类型、字符串类型等。

1.1定义常量的语法 ​

const ​

定义一个常量使用const关键字，语法格式如下

go
const constantName [type]= value

const：定义常量关键字
constName: 常量名称
type： 常量类型
value：常量值

//例子
package main

func main() {
    const PI float64 = 3.14
    const PI = 3.1415 //可以省略类型
    
    const (
    	width = 100
    	height = 100
    )
    const i, j = 1, 2 //多重赋值
    const a , b , c = 1, 2, "foo"
}
const constantName [type]= value

const：定义常量关键字
constName: 常量名称
type： 常量类型
value：常量值

//例子
package main

func main() {
    const PI float64 = 3.14
    const PI = 3.1415 //可以省略类型
    
    const (
    	width = 100
    	height = 100
    )
    const i, j = 1, 2 //多重赋值
    const a , b , c = 1, 2, "foo"
}

const同时声明多个常量时，如果省略了值则表示和上面一行的值相同

go
package main

import "fmt"

func main() {
    const (
    	a1 = 100
        a2
        a3
    )
    fmt.Printf("a1: %v\n",a1)
    fmt.Printf("a2: %v\n",a2)
    fmt.Printf("a3: %v\n",a3)
}
package main

import "fmt"

func main() {
    const (
    	a1 = 100
        a2
        a3
    )
    fmt.Printf("a1: %v\n",a1)
    fmt.Printf("a2: %v\n",a2)
    fmt.Printf("a3: %v\n",a3)
}

iota ​

iota比较特殊，可以被认为是一个可被编译器修改的常量，它默认开始值是0，每调用一次加1。遇到const关键字时被重置为0.

go
package main

import "fmt"

func main() {
    const (
    	a1 = iota
        a2 = iota
        a3 = iota
    )
     fmt.Printf("a1: %v\n",a1)
    fmt.Printf("a2: %v\n",a2)
    fmt.Printf("a3: %v\n",a3)
}
package main

import "fmt"

func main() {
    const (
    	a1 = iota
        a2 = iota
        a3 = iota
    )
     fmt.Printf("a1: %v\n",a1)
    fmt.Printf("a2: %v\n",a2)
    fmt.Printf("a3: %v\n",a3)
}
  • 使用_跳过某些值
go
package main
import "fmt"

func main() {
    const (
    	a1 = iota
        _
        a3 = iota
    )
    fmt.Printf("a1: %v\n",a1)
    fmt.Printf("a2: %v\n",a2)
}
package main
import "fmt"

func main() {
    const (
    	a1 = iota
        _
        a3 = iota
    )
    fmt.Printf("a1: %v\n",a1)
    fmt.Printf("a2: %v\n",a2)
}
  • 声明中间插队
go
package main

import "fmt"

func main(){
	const (
		a1 = iota
		a2 = 100
		a3 = iota
	)
	fmt.Printf("a1: %v\n",a1)
    fmt.Printf("a2: %v\n",a2)
    fmt.Printf("a3: %v\n",a3)
}
package main

import "fmt"

func main(){
	const (
		a1 = iota
		a2 = 100
		a3 = iota
	)
	fmt.Printf("a1: %v\n",a1)
    fmt.Printf("a2: %v\n",a2)
    fmt.Printf("a3: %v\n",a3)
}

https://www.bilibili.com/video/BV1zR4y1t7Wj/?p=11&vd_source=271cfb4bb43eae8c9b0543f4ae14ec31

https://www.cnblogs.com/liangyun/p/goland.html

https://blog.jetbrains.com/go/2019/09/11/increase-productivity-with-custom-postfix-completion-templates/

https://gitee.com/wuyumin/GoLand/blob/master/Skill.md

https://blog.csdn.net/le_17_4_6/article/details/123988756

http://c.biancheng.net/view/6216.html