Go's rand
package makes it easy to generate all sorts of random numbers.
What they don't tell you though is that the default seed is 1
. So if you
write a program like so:
package main
import "fmt"
import "math/rand"
func main() {
stuff := []string{
"one",
"two",
"three",
"four",
}
fmt.Println(stuff[rand.Intn(len(stuff))])
}
and then run it, you will get output like:
three
and any subsequent runs of the program will continue to produce three
. Not
exactly what we are looking for.
If you want your program to be a little less predictable, you will want to
seed it yourself, perhaps with the current time, instead of 1
. Try adding
the following to the beginning of the main
function:
rand.Seed( time.Now().UTC().UnixNano())
You'll also want to import the time
package.
Things should appear to be a bit more random now.
source: Jake Worth and Stackoverflow