Master Golang: Random Numbers

Go’s `math/rand` package provides pseudorandom number generation.
	package main
	import ( "fmt" "math/rand" "time" )
	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()
The default number generator is deterministic, so it’ll produce the same sequence of numbers each time by default. To produce varying sequences, give it a seed that changes. Note that this is not safe to use for random numbers you intend to be secret; use `crypto/rand` for those.	s1 := rand.NewSource(time.Now().UnixNano()) r1 := rand.New(s1)
Call the resulting `rand.Rand` just like the functions on the `rand` package.	fmt.Print(r1.Intn(100), ",") fmt.Print(r1.Intn(100)) fmt.Println()
If you seed a source with the same number, it produces the same sequence of random numbers.	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)) }

Depending on where you run this sample, some of the generated numbers may be different. Note that on the Go playground seeding with `time.Now()` still produces deterministic results due to the way the playground is implemented.	$ go run random-numbers.go 81,87 0.6645600532184904 7.123187485356329,8.434115364335547 0,28 5,87 5,87
See the `math/rand` package docs for references on other random quantities that Go can provide.

Next example: Number Parsing.