Assume the following:
class A {
let x : Int
init() {
self.x = assign(1)
}
func assign(y : Int) -> Int {
return y
}
}
This produces an error.
Here is my question : is there a way to call functions within the class initializer?
EDIT: Added error message:
use of 'self' in method call 'assign' before all stored properties are initialized
One other (possibly helpful) option is to have the function you call within the initializer scope:
class A {
let x : Int
init() {
func assign(y : Int) -> Int {
return y
}
self.x = assign(y: 1)
}
}
I'm doing that in a project right now. I have a large initializer (its actually a parser) and use an initializer-scoped function for error reporting. Of course, I'd prefer the function to be at class scope so I can reuse it between initializers. But at least I can reuse it within each initializer.
You can't call instance methods until the instance is initialized (before init is done), but you can use module-level functions and type methods defined using the class or static keyword.
func compute(y: Int) -> Int {
return y
}
class A {
let x: Int
static func assign(y: Int) -> Int {
return y
}
init () {
x = A.assign(3) + compute(4)
}
}
I think it is not the greatest solution but still it is working.
class A {
var variable : Int
init() {
self.variable = A.assign(1)
}
private class func assign(y : Int) -> Int {
return y
}
}
You could use somethings like:
class A {
var x : Int!
init() {
x = assign(1)
}
func assign(y : Int) -> Int {
return y
}
}
The downside of this approach is that you will get a runtime error if you access x and it is not initialised. Check out this answer.
x is optional so the error doesn't apply anymore. Now you do not use self before all stored properties are initialised because you do not have such properties anymore, now they are optionals.