Skip to main content

NOTICE: On Friday Nov 6, Workspaces will be temporarily unavailable for maintenance.

🚀 In our NEW AI Bootcamp you'll build a working app in 28 days, no experience required. Free to all subscription levels.

✨ Earn college credits in Cybersecurity, JS, HTML, CSS and Python

Join the Treehouse affiliate program and earn 25% recurring commission! 🤑

  • Treehouse Logo
    • For Individuals
    • For Businesses
    • For Schools
    • For Libraries
    • For Military
    • All Courses
    • Tracks
    • AI Bootcamp
    • College Credit
    • Techdegree Bootcamps
    • Front End Development
    • Full Stack JavaScript
    • Code Adventures
    • Discord
    • Forum
    • Success Stories
    • Treehouse Links
    • 100 Days of Code
    • Explore
    • Career Toolbox
    • Free Treehouse Near Me
    • Affiliates
    • Blog
    • Support
    • About
    • Learn
    • Beginner's Guide to Coding
    • Data Analysis with SQL & Python
    • Front-End Web Development
    • Python Programming Basics
    • Techdegree Bootcamp Overview
    • UX Design Fundamentals
    • AI Tools for Beginners
  • For Individuals For Businesses For Schools For Libraries For Military
  • All Courses Tracks AI Bootcamp College Credit
  • Techdegree Bootcamps Front End Web Development Full Stack JavaScript
  • Code Adventures Discord Forum Success Stories Treehouse Links 100 Days of Code
  • Explore Career Toolbox Free Treehouse Near Me Affiliates Blog Support About
    Learn Beginner's Guide to Coding Data Analysis with SQL & Python Front-End Web Development Python Programming Basics Techdegree Bootcamp Overview UX Design Fundamentals AI Tools for Beginners
  • Sign In
  • Free Trial
Instagram Twitter Facebook YouTube LinkedIn
Loading banner... Start your free trial at Treehouse
    • Newest
      • Newest
      • Active
      • Unanswered
      • Featured
    • All Topics
      • All Topics
      • • General Discussion
      • • AI
      • • APIs
      • • Coding for Kids
      • • College Credit
      • • Computer Science
      • • CSS
      • • Data Analysis
      • • Databases
      • • Design
      • • Development Tools
      • • Digital Literacy
      • • Game Development
      • • Go Language
      • • HTML
      • • Java
      • • JavaScript
      • • Learning Resources
      • • Machine Learning
      • • No-Code
      • • PHP
      • • Professional Growth
      • • Python
      • • Quality Assurance
      • • React
      • • Ruby
      • • Security
      • • Swift
      • • Vibe Coding
  • Tommy Choe
    Tommy Choe
    38,156 Points

    @teamtreehouse Wrong link provided in the teachers notes

    Posted October 19, 2015 7:38pm by Tommy Choe
    Tommy Choe
    38,156 Points
    • iOS
    • Object-Oriented Swift
    • Properties
    • Optional Property

    0 Answers

  • Alexander Certosimo
    Alexander Certosimo
    1,774 Points

    confused with optional property in lesson compared to my xcode

    Posted August 17, 2015 3:16am by Alexander Certosimo
    Alexander Certosimo
    1,774 Points
    • iOS
    • Object-Oriented Swift
    • Properties
    • Optional Property

    1 Answer

  • Leonardo Santos
    Leonardo Santos
    5,290 Points

    Changing the value of a constant

    Posted August 1, 2015 11:33pm by Leonardo Santos
    Leonardo Santos
    5,290 Points
    • iOS
    • Object-Oriented Swift
    • Properties
    • Optional Property

    3 Answers

  • GIUSEPPE GRAMMATICO
    GIUSEPPE GRAMMATICO
    9,255 Points

    How to check optional is nil?

    Posted July 31, 2015 12:01pm by GIUSEPPE GRAMMATICO
    GIUSEPPE GRAMMATICO
    9,255 Points
    • iOS
    • Object-Oriented Swift
    • Properties
    • Optional Property

    2 Answers

  • dexter foo
    dexter foo
    8,233 Points

    Not really following how the if let statement works in this case

    Posted July 21, 2015 6:20am by dexter foo
    dexter foo
    8,233 Points
    • iOS
    • Object-Oriented Swift
    • Properties
    • Optional Property

    3 Answers

  • andrew park
    andrew park
    2,733 Points

    Both these work on my playground should I use the second celsius = (newValue + 32)/1.8 celsius = newValue

    Posted February 15, 2015 10:10pm by andrew park
    andrew park
    2,733 Points
    • iOS
    • Object-Oriented Swift
    • Properties
    • Optional Property

    2 Answers

  • Shawn Bolour
    Shawn Bolour
    2,423 Points

    Optional Property

    Posted February 12, 2015 3:01pm by Shawn Bolour
    Shawn Bolour
    2,423 Points
    • iOS
    • Object-Oriented Swift
    • Properties
    • Optional Property

    2 Answers

Posting to the forum is only allowed for members with active accounts.
Please sign in or sign up to post.

Techdegree

  • Front End Web Development
  • Full Stack JavaScript
SEE ALL

Tracks

  • Learn to Code for Beginners
  • Beginning Python
  • Beginning SQL
  • Beginning Java
SEE ALL

Courses

  • JavaScript Basics
  • Intro to HTML & CSS
  • Python Basics
  • CSS Layout
SEE ALL

About Us

  • About
  • Blog
  • Community
  • Stories
  • Contact
  • Gift Card

Explore

  • Plans
  • Affiliates
  • Perks
  • Shop
  • Free Treehouse Near Me
  • Treehouse for Libraries
  • Treehouse for Businesses

Treehouse is an online technology education platform founded in 2011. Treehouse offers more than 700 self-paced, video-based courses in web development, programming, data analysis, design, and AI, plus two project-based bootcamp programs in Front End Web Development and Full Stack JavaScript. Individual Treehouse plans start at $25 per month and include a 7-day free trial. Treehouse serves individual learners, businesses, schools, and public libraries. Cardholders at participating U.S. public libraries can use Treehouse for free. Select Treehouse courses, offered with University Pathways International, are recommended for college credit by ACE and NCCRS. Treehouse learners earn digital certificates for completed Tracks.

Terms & Conditions · Privacy · © 2026 Treehouse Island, Inc.
  • Twitter
  • YouTube
  • Facebook
  • LinkedIn
  • Instagram
  • Discord