Random Numbers #

// Go's `math/rand/v2` package provides
// [pseudorandom number](https://en.wikipedia.org/wiki/Pseudorandom_number_generator)
// generation.

package main

import (
	"fmt"
	"math/rand/v2"
)

func main() {

	// For example, `rand.IntN` returns a random `int` n,
	// `0 <= n < 100`.
	fmt.Print(rand.IntN(100), ",")
	fmt.Print(rand.IntN(100))
	fmt.Println()

	// `rand.Float64` returns a `float64` `f`,
	// `0.0 <= f < 1.0`.
	fmt.Println(rand.Float64())

	// This 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()

	// If you want a known seed, create a new
	// `rand.Source` and pass it into the `New`
	// constructor. `NewPCG` creates a new
	// [PCG](https://en.wikipedia.org/wiki/Permuted_congruential_generator)
	// source that requires a seed of two `uint64`
	// numbers.
	s2 := rand.NewPCG(42, 1024)
	r2 := rand.New(s2)
	fmt.Print(r2.IntN(100), ",")
	fmt.Print(r2.IntN(100))
	fmt.Println()

	s3 := rand.NewPCG(42, 1024)
	r3 := rand.New(s3)
	fmt.Print(r3.IntN(100), ",")
	fmt.Print(r3.IntN(100))
	fmt.Println()
}

# Some of the generated numbers may be
# different when you run the sample.
$ go run random-numbers.go
68,56
0.8090228139659177
5.840125017402497,6.937056298890035
94,49
94,49

# See the [`math/rand/v2`](https://pkg.go.dev/math/rand/v2)
# package docs for references on other random quantities
# that Go can provide.