Generating random numbers

This recipe shows how to generate random numbers. This functionality is provided by the math/rand package. The random numbers generated by math/rand are considered cryptographically insecure because the sequences are repeatable with given seed.

To generate cryptographically secure numbers, the crypto/rand package should be used. These sequences are not repeatable.

 

How to do it...

1. Open the console and create the folder chapter03/recipe08.
2. Navigate to the directory.
3. Create the rand.go file with the following content:

        package main

        import (
          crypto "crypto/rand"
          "fmt"
          "math/big"
          "math/rand"
        )

        func main() {

          sec1 := rand.New(rand.NewSource(10))
          sec2 := rand.New(rand.NewSource(10))
          for i := 0; i < 5; i++ {
            rnd1 := sec1.Int()
            rnd2 := sec2.Int()
            if rnd1 != rnd2 {
              fmt.Println("Rand generated non-equal sequence")
         ...