go 基础 变量和常量

package main

import "fmt"
//全局变量，赋值
var(
   PI float32 = 3.1415
   Count int = 56
)

//全局变量，无值
var(
   x string
   y string
)

func main() {
    var i1 = true
    var i2 bool = true
    var i3 bool   //默认false
    i4 := true

    var i5,i6 = 1,2   //类型相同多个变量, 非全局变量
    var i7,i8 int
    i7,i8 = 1,2
   i9,i10 := 1,2
   var i11,i12 = true,  "123"  //不同类型相同多个变量, 非全局变量

   fmt.Println(PI)
   fmt.Println(Count)

   x = "xxxxx"
   y = "yyyyy"
   fmt.Println(x)
   fmt.Println(y)

   fmt.Println(i1)
   fmt.Println(i2)
   fmt.Println(i3)
   fmt.Println(i4)
   fmt.Println(i5)
   fmt.Println(i6)
   fmt.Println(i7)
   fmt.Println(i8)
   fmt.Println(i9)
   fmt.Println(i10)
   fmt.Println(i11)
   fmt.Println(i12)
   fmt.Println("Hello, World2!")
}

 

package main

const PI  = 3.1415
const Earth  = 6371
const (
    X = 3.14
    Y = 6371
)

func main() {
    println(PI)
    println(Earth)
    println(X)
    println(Y)
}