Skip to main content

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

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

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

  • 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
  • abidghani
    abidghani
    4,954 Points

    Objective-C Protocols

    Posted May 14, 2015 6:56pm by abidghani
    abidghani
    4,954 Points
    • iOS
    • Objective-C Basics (Retired)
    • Advanced Objective-C
    • Categories

    1 Answer

  • Kristin Day
    Kristin Day
    1,450 Points

    When I go to create a category, my options are not the same as the ones on this video. I can't find the option.

    Posted March 11, 2015 11:43pm by Kristin Day
    Kristin Day
    1,450 Points
    • iOS
    • Objective-C Basics (Retired)
    • Advanced Objective-C
    • Categories

    1 Answer

  • Swapnil Kapse
    Swapnil Kapse
    1,162 Points

    Issue while trying this tutorial related to categories in xcode6

    Posted November 4, 2014 9:40pm by Swapnil Kapse
    Swapnil Kapse
    1,162 Points
    • iOS
    • Objective-C Basics (Retired)
    • Advanced Objective-C
    • Categories

    3 Answers

  • Caleb Kleveter
    Caleb Kleveter
    37,862 Points

    what is this warning?

    Posted October 27, 2014 3:30pm by Caleb Kleveter
    Caleb Kleveter
    37,862 Points
    • iOS
    • Objective-C Basics (Retired)
    • Advanced Objective-C
    • Categories

    2 Answers

  • Caleb Kleveter
    Caleb Kleveter
    37,862 Points

    How do I make my files the same as shown in the video?

    Posted October 24, 2014 5:40pm by Caleb Kleveter
    Caleb Kleveter
    37,862 Points
    • iOS
    • Objective-C Basics (Retired)
    • Advanced Objective-C
    • Categories

    1 Answer

  • Caleb Kleveter
    Caleb Kleveter
    37,862 Points

    Why do I have extra files in Xcode?

    Posted October 23, 2014 8:46pm by Caleb Kleveter
    Caleb Kleveter
    37,862 Points
    • iOS
    • Objective-C Basics (Retired)
    • Advanced Objective-C
    • Categories

    1 Answer

  • Don Noray
    Don Noray
    19,238 Points

    There is no Coca Touch under iOS

    Posted September 30, 2014 6:13pm by Don Noray
    Don Noray
    19,238 Points
    • iOS
    • Objective-C Basics (Retired)
    • Advanced Objective-C
    • Categories

    0 Answers

  • Michael Burton
    PLUS
    Michael Burton
    Courses Plus Student 1,710 Points

    Creating a category in Xcode 6.0 beta

    Posted August 18, 2014 9:38am by Michael Burton
    Michael Burton
    Courses Plus Student 1,710 Points
    • iOS
    • Objective-C Basics (Retired)
    • Advanced Objective-C
    • Categories

    1 Answer

  • Mohammad Baqer
    Mohammad Baqer
    4,260 Points

    Why dont we simply add that method to the original NSArray class

    Posted July 6, 2014 1:27pm by Mohammad Baqer
    Mohammad Baqer
    4,260 Points
    • iOS
    • Objective-C Basics (Retired)
    • Advanced Objective-C
    • Categories

    1 Answer

  • Chee Mervin
    PLUS
    Chee Mervin
    Courses Plus Student 4,195 Points

    Category object for incrementing all items in a mutable array

    Posted June 15, 2014 8:37am by Chee Mervin
    Chee Mervin
    Courses Plus Student 4,195 Points
    • iOS
    • Objective-C Basics (Retired)
    • Advanced Objective-C
    • Categories

    3 Answers

  • Jared Watkins
    Jared Watkins
    10,756 Points

    nonatomic

    Posted March 4, 2014 12:08am by Jared Watkins
    Jared Watkins
    10,756 Points
    • iOS
    • Objective-C Basics (Retired)
    • Advanced Objective-C
    • Categories

    1 Answer

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