random-numbers.go

// math/rand package provides pseudorandom number generation

package main

import "time"
import "fmt"
import "math/rand"

func main() {

  // rand.Intn return a random int n, 0 <= n < 100
  fmt.Print(rand.Intn(100), ",")
  fmt.Print(rand.Intn(100))
  fmt.Println()
  
  //rand.Float64 returns a float64, 0.0 <= f < 1.0
  fmt.Println(rand.Float64())
  
  // can be used to generate random floats in other ranges
  // for example 5.0 <= f < 10.0
  fmt.Print((rand.Float64()*5)+5, ",")
  fmt.Print((rand.Float64() * 5) + 5)
  fmt.Println()
  
  s1 := rand.NewSource(time.Now().UnixNano())
  r1 := rand.New(s1)
  
  fmt.Print(r1.Intn(100), ",")
  fmt.Print(r1.Intn(100))
  fmt.Println()
  
  s2 := rand.NewSource(42)
  r2 := rand.New(s2)
  fmt.Print(r2.Intn(100), ",")
  fmt.Print(r2.Intn(100))
  fmt.Println()
  s3 := rand.NewSource(42)
  r3 := rand.New(s3)
  fmt.Print(r3.Intn(100), ",")
  fmt.Print(r3.Intn(100))
}