A Tour of Go Numeric Constants

川长思鸟来 2022-01-07 07:05 296阅读 0赞

Numeric constants are high-precision values.

An untyped constant takes the type needed by its context.

Try printing needInt(Big) too.

  1. package main 
  3. import "fmt"
  5. const (
  6.     Big = 1 << 100
  7.     Small = Big >> 99
  8. )
  10. func needInt(x int) int {
  11.     return x*10 + 1
  12. }
  14. func needFloat(x float64) float64{
  15.     return x * 0.1
  16. }
  18. func main() {
  19.     fmt.Println(needInt(Small))
  20.     fmt.Println(needFloat(Small))
  21.     fmt.Println(needFloat(Big))
  22. }
  24. package main 
  26. import "fmt"
  28. const (
  29.     Big = 1 << 100
  30.     Small = Big >> 99
  31. )
  33. func needInt(x int) int {
  34.     return x*10 + 1
  35. }
  37. func needFloat(x float64) float64{
  38.     return x * 0.1
  39. }
  41. func main() {
  42.     fmt.Println(Small);
  43.     var intVariable int = 1
  44.     //var float32Variable float32 = 1.2
  45.     fmt.Println(needInt(Small))
  46.     // constant 1267650600228229401496703205376 overflows int
  47.     //fmt.Println(needInt(Big))
  48.     fmt.Println(needFloat(Small))
  49.     fmt.Println(needFloat(Big))
  51.     //go语言对类型的要求是很严格的，所以你不能传递int到float中或者float到int
  52.     fmt.Println(needInt(intVariable))
  53.     //cannot use float32Variable (type float32) as type int in argument to needInt
  54.     //fmt.Println(needInt(float32Variable))
  55.     //cannot use intVariable (type int) as type float64 in argument to needFloat
  56.     //fmt.Println(needFloat(intVariable))
  57.     //cannot use float32Variable (type float32) as type float64 in argument to needFloat
  58.     //fmt.Println(needFloat(float32Variable))
  60. }

不过常量却相对宽容一些

  1. //constant 1267650600228229401496703205376 overflows int
  2.     fmt.Println(Big);

转载于:https://www.cnblogs.com/ghgyj/p/4052714.html

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