Difficulties to assign default value to a parameter of a function

Question

In a class, I defined a private constant, I try to use the constant as a default value of parameter of a function:

class Foo {
  // instance variable
  priva         


        

Answer 1

I don't think that is possible. The default value is inserted at the calling site, and therefore needs to be public, see also Access control in swift 4.

A possible workaround would be to make the parameter optional, and substitute nil by the default value locally:

class Foo {
    private static let DefaultValue = 10

    public func doTask(amount: Int? = nil) {
        let amount = amount ?? Foo.DefaultValue
        // ...
    }
}