Go on Jake Worth

Seeding Golang's Rand

Fri, 25 Sep 2015 08:04:38 -0500

‘Random’ numbers in Go don’t always seem random. This is because the rand package defaults to a seed of 1.

That’s great if you need a bunch of random numbers at the start of your program. Not great if you expect a different outcome each time you run the program.

A solution is to seed rand with Unix time. Try it in the init() function:

package main

import (
 "math/rand"
 "time"
)

func init() {
 rand.Seed(time.Now().UTC().UnixNano())
}
...

Go iota

Thu, 17 Sep 2015 13:24:16 -0500

Go has an interesting feature called iota. When declaring a list of constants, this keyword represents successive untyped integer constants.

const (
 foo = iota // foo == 0
 bar = iota // bar == 1
 baz = iota // baz == 2
)

Anytime const is invoked, the counter resets.

const foo = iota // foo == 0
const bar = iota // bar == 0

This is a cool way to quickly define a list of integer constants, such as ’true’ and ‘false’, for later use.