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iOS Build a Simple iPhone App with Swift Getting Started with iOS Development Swift Recap Part 1

Richard Sun
Richard Sun
11,257 Points
Posted by Richard Sun
Richard Sun
11,257 Points

Why does it say to use String Interpolation if I am already using it?

I've tried different things, like trying to return the String without storing it first. I don't know what I'm doing wrong.

structs.swift 
struct Tag {
  let name: String
}

struct Post {
  var title: String
  let author: String
  var tag: Tag

  init (title: String, author: String, tag: Tag) {
    self.title = title
    self.author = author
    self.tag = tag
  }

  func description () -> String {
    let description = "\(title) by \(author). Filed under \(tag)"
    return description
  }
}

let firstPost = Post(title: "iOS Development", author: "Apple", tag: Tag(name: "swift"))
let postDescription: String = firstPost.description()

1 Answer

Jason Anders
MOD
Jason Anders
Treehouse Moderator 145,860 Points
Jason Anders
Jason Anders
Treehouse Moderator 145,860 Points

Hey Richard,

It's sort of a misleading error, as the main problem lies inside the instance method and not the actual interpolation of the string (though there is an error in there too).

  1. The method itself is called description. The challenge did not ask you to assign the interpolated string to a constant called the same. You just need to return the string, so you're 2 lines should only be one.
  2. The compiler won't let you just interpolate tag without the member. So... it needs name which is the member you want in the string.

I have provided the corrected method for you to review. Have a look and what was changed and also why.

func description () -> String {
    return "\(title) by \(author). Filed under \(tag.name)"
  }

Keep Coding! :) :dizzy: