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iOS Build a Weather App with Swift Interacting with Data From the Web Constructing a URL

Posted by Grant Powell
Grant Powell
2,356 Points

String interpolation is not working. Getting unknown error.

Line 2 should work but does not.

let treehouseBaseURL = NSURL(string: "https://api.teamtreehouse.com/")

let courseURL = NSURL(string: "course/(COURSE_ID)", relativeToURL: treehouseBaseURL)

urls.swift 
import Foundation

let treehouseCourseID = 25

// Add your code below
let treehouseBaseURL  = NSURL(string: "https://api.teamtreehouse.com/")
let courseURL = NSURL(string: "course/\(COURSE_ID)", relativeToURL: treehouseBaseURL)

3 Answers

Grant Powell
Grant Powell
2,356 Points

Got it, thanks.

Incidentally, it turned out the instructions were wrong. It was instruction me to use "courseID" as the variable name, but as you see in the code, the variable name is actually "treehouseCourseID".

Greg Kaleka
Greg Kaleka
39,021 Points
Greg Kaleka
Greg Kaleka
39,021 Points

Oh interesting - after you complete a challenge, there's a link on the pop-up giving you your points where you can leave feedback. If you run into problems like this one, make sure you leave feedback.

Pasan Premaratne, you may want to have a quick look at this challenge's wording.

Greg Kaleka
Greg Kaleka
39,021 Points
Greg Kaleka
Greg Kaleka
39,021 Points

Hi Grant,

There's no variable in your code named COURSE_ID, so Swift has no idea what you want there. If you're trying to pass in treehouseCourseID, you have to use that.

import Foundation

let treehouseCourseID = 25

// Add your code below
let treehouseBaseURL  = NSURL(string: "https://api.teamtreehouse.com/")
let courseURL = NSURL(string: "course/\(treehouseCourseID)", relativeToURL: treehouseBaseURL)
Grant Powell
Grant Powell
2,356 Points
Grant Powell
Grant Powell
2,356 Points

There's no variable in your code named COURSE_ID, so Swift has no idea what you want there. If you're trying to pass in treehouseCourseID, you have to use that.