Golang init

Initializing Packages on Import

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

Above init codes ensure the initialization are performed prior to the package being used.

Multiple Instances of init()

The init() function can be declared multiple times throughout a package.

In most cases, init() functions will execute in the order that you encounter them.

You can put init() in several files. They will be compiled in the alphabetical order of file names.

Using init() for Side Effects

// --snip--
import _ "image/png"

// --snip--

Because GO doesn't allow you to import packages that are not used throughout the program. This import line will only run the init() function of image/png package and discard the value of import itself. This is called importing for side effect.