Search code examples
oopconstructorgo

Constructors in Go

I have a struct and I would like it to be initialised with some sensible default values.

Typically, the thing to do here is to use a constructor but since go isn't really OOP in the traditional sense these aren't true objects and it has no constructors.

I have noticed the init method but that is at the package level. Is there something else similar that can be used at the struct level?

If not what is the accepted best practice for this type of thing in Go?

Solution

  • There are actually two accepted best practices:

    1. Make the zero value of your struct a sensible default. (While this looks strange to most people coming from "traditional" oop it often works and is really convenient).
    2. Provide a function func New() YourTyp or if you have several such types in your package functions func NewYourType1() YourType1 and so on.

    Document if a zero value of your type is usable or not (in which case it has to be set up by one of the New... functions. (For the "traditionalist" oops: Someone who does not read the documentation won't be able to use your types properly, even if he cannot create objects in undefined states.)