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iOS Intermediate Swift Extensions and Protocols Extending a Native Type

Extending a Native Type Code Challenge

Every time I check my work it says, "Bummer: Make sure you're adding an add method that takes an Int and returns an Int?" I am pretty sure my syntax is correct, and I don't know what I am doing wrong.

Magnus Hållberg
Magnus Hållberg
17,232 Points

Could you post your code, otherwise its hard to help.

Sorry, I thought it was on there. Here it is:

extension String {
  func add(_ value: Int) -> Int {
    if let intValue = Int(Self) {
      return intValue + value
    } else {
      return nil
    }
  }
}

3 Answers

Magnus Hållberg
Magnus Hållberg
17,232 Points

There are some small mistakes. First, your return has to be optionall so its Int? not just Int. Also ”self” is spelled with lower case letters. Hope this helps

I tried that, but it's still saying the same thing. I've even tried other people's answers that they said worked, but it still does this.

Magnus Hållberg
Magnus Hållberg
17,232 Points

This is not an actual error but you have omitted the external label in the method, remove that and you will pass. I used your code above and removed the omitted label, changed the return to make it optional and wrote self in lower case letters and that passed the challenge.

Ok, now it worked. Thanks!