go 变量定义

package main

import (
   "fmt"
   "math"
   "math/cmplx"
)

func varValues() {
   var a int
   var b string
   fmt.Printf("%d %q\n", a, b)
}

func varchuValues() {
   var a int = 3
   var s string = "abc"
   fmt.Println(a, s)
}

func varquType() {
   var a,b,c,d = 3,4,true,"def"
   var s = "abc"
   fmt.Println(a,b,c,d, s)
}

func varduanValues()  {
   a,b,c,d := 3,4,true,"def"
   b = 5
   fmt.Println(a,b,c,d)
}

var (
   aa = 9
   bb = "bb123"
   cc = true
)

//欧拉公式
func euler()  {
   //c := 3 +4i
   //fmt.Println(cmplx.Abs(c))
   fmt.Printf("%.3f\n",cmplx.Exp(1i*math.Pi) + 1)
}

func qiangzhi() {
   var a, b int = 5, 5
   var c int
   c = int(math.Sqrt( float64(a * a + b * b)))
   fmt.Println(c)
}

func consts() {
   const a, b = 3, 4
   var c int
   c = int(math.Sqrt(a * a + b * b))
   fmt.Println(c)
}

func enums() {
   const (
      b = 1 << (10 * iota)
      kb
      mb
      gb
      tb
   )
   fmt.Println(b,kb,mb,gb,tb)
}

func main() {
   fmt.Println("hello world")
   varValues()
   varchuValues()
   varquType()
   varduanValues()
   fmt.Println(aa,bb,cc)

   euler()

   qiangzhi()

   consts()
   enums()
}