Mastering Go - Second Edition

The init() function

Every Go package can optionally have a private function named init() that is automatically executed at the beginning of the execution time.

The init() function is a private function by design, which means that it cannot be called from outside the package in which it is contained. Additionally, as the user of a package has no control over the init() function, you should think carefully before using an init() function in public packages or changing any global state in init().

I will now present a code example with multiple init() functions from multiple Go packages. Examine the code of the following basic Go package, which is simply called a:

package a import ( "fmt" ) func init() { fmt.Println("init() a") } func FromA() ...