Objective-C

1,697 students

29 contributors

1,695
students have developed their Objective-C skills on Exercism.

Students

1,695

Submissions

1,788

Mentoring Discussions

74

The Objective-C track needs attention ⚠️

Building

Build

Use your knowledge to build the Objective-C track itself

29 contributors

Build Test Runners

Create Test Runners that have the single responsibility of taking a solution, running all tests and returning a standardized output.

Next goal: Build a Test Runner. Find out more.

Build Analyzers

Build an Analyzer for Objective-C: Exercism's analyzers automatically assess student's submissions and provide mentor-style commentary.

Next goal: Build an Analyzer. Find out more.

Build Representers

Build a Representer: a bit of code that has the single responsibility of taking a solution and returning a normalized representation of it.

Next goal: Build a Representer. Find out more.

Create Practice Exercises

Practice Exercises are exercises designed to allow students to solve an arbitrary problem, with the aim of them making use of the concepts they have learned so far.

Next goal: Implement 129 practice exercises. Find out more.

Usage statistics

51 active practice exercises

Started

Attempts

Completions

Mentoring requests

Hello World

480

351 (avg. 0.7)

246 (51.2%)

0 (0.0%)

Bob

228

283 (avg. 1.2)

185 (81.1%)

21 (9.2%)

Difference of Squares

55

64 (avg. 1.2)

42 (76.4%)

5 (9.1%)

Gigasecond

52

58 (avg. 1.1)

42 (80.8%)

3 (5.8%)

Leap

76

85 (avg. 1.1)

63 (82.9%)

5 (6.6%)

Reverse String

38

37 (avg. 1.0)

26 (68.4%)

1 (2.6%)

Space Age

37

34 (avg. 0.9)

30 (81.1%)

1 (2.7%)

Sum of Multiples

42

48 (avg. 1.1)

32 (76.2%)

1 (2.4%)

Two Fer

105

101 (avg. 1.0)

57 (54.3%)

27 (25.7%)

ETL

32

32 (avg. 1.0)

25 (78.1%)

0 (0.0%)

Flatten Array

21

25 (avg. 1.2)

15 (71.4%)

0 (0.0%)

Grade School

41

43 (avg. 1.0)

31 (75.6%)

0 (0.0%)

Hamming

91

108 (avg. 1.2)

84 (92.3%)

4 (4.4%)

Isogram

18

24 (avg. 1.3)

14 (77.8%)

0 (0.0%)

Nucleotide Count

41

49 (avg. 1.2)

37 (90.2%)

3 (7.3%)

Prime Factors

15

12 (avg. 0.8)

9 (60.0%)

0 (0.0%)

Raindrops

38

37 (avg. 1.0)

26 (68.4%)

3 (7.9%)

RNA Transcription

10

12 (avg. 1.2)

7 (70.0%)

0 (0.0%)

Atbash Cipher

11

12 (avg. 1.1)

8 (72.7%)

0 (0.0%)

Clock

13

12 (avg. 0.9)

8 (61.5%)

0 (0.0%)

Collatz Conjecture

8

8 (avg. 1.0)

5 (62.5%)

0 (0.0%)

Grains

8

8 (avg. 1.0)

6 (75.0%)

0 (0.0%)

Perfect Numbers

11

9 (avg. 0.8)

8 (72.7%)

0 (0.0%)

Phone Number

26

28 (avg. 1.1)

24 (92.3%)

1 (3.8%)

Robot Name

27

28 (avg. 1.0)

21 (77.8%)

0 (0.0%)

Scrabble Score

13

11 (avg. 0.8)

8 (61.5%)

0 (0.0%)

Secret Handshake

8

7 (avg. 0.9)

5 (62.5%)

0 (0.0%)

Series

8

3 (avg. 0.4)

3 (37.5%)

0 (0.0%)

Sieve

8

6 (avg. 0.8)

5 (62.5%)

0 (0.0%)

Strain

8

6 (avg. 0.8)

5 (62.5%)

0 (0.0%)

Sublist

15

14 (avg. 0.9)

10 (66.7%)

0 (0.0%)

Triangle

13

8 (avg. 0.6)

7 (53.8%)

0 (0.0%)

Acronym

10

9 (avg. 0.9)

7 (70.0%)

0 (0.0%)

All Your Base

13

8 (avg. 0.6)

8 (61.5%)

0 (0.0%)

Allergies

10

11 (avg. 1.1)

7 (70.0%)

0 (0.0%)

Anagram

39

49 (avg. 1.3)

36 (92.3%)

1 (2.6%)

Beer Song

12

11 (avg. 0.9)

9 (75.0%)

0 (0.0%)

Binary Search

8

8 (avg. 1.0)

4 (50.0%)

0 (0.0%)

Crypto Square

7

3 (avg. 0.4)

3 (42.9%)

0 (0.0%)

Largest Series Product

8

6 (avg. 0.8)

5 (62.5%)

0 (0.0%)

Meetup

9

7 (avg. 0.8)

4 (44.4%)

0 (0.0%)

Nth Prime

8

7 (avg. 0.9)

4 (50.0%)

0 (0.0%)

Pangram

10

5 (avg. 0.5)

5 (50.0%)

0 (0.0%)

Pascal's Triangle

7

7 (avg. 1.0)

4 (57.1%)

0 (0.0%)

Say

5

2 (avg. 0.4)

2 (40.0%)

0 (0.0%)

Transpose

6

3 (avg. 0.5)

3 (50.0%)

0 (0.0%)

Word Count

51

65 (avg. 1.3)

48 (94.1%)

2 (3.9%)

Matching Brackets

8

7 (avg. 0.9)

4 (50.0%)

0 (0.0%)

Luhn

10

8 (avg. 0.8)

5 (50.0%)

0 (0.0%)

Roman Numerals

6

4 (avg. 0.7)

4 (66.7%)

0 (0.0%)

Run-Length Encoding

10

5 (avg. 0.5)

5 (50.0%)

0 (0.0%)

78 unimplemented practice exercises

Affine Cipher

Alphametics

Armstrong Numbers

Bank Account

Binary Search Tree

Book Store

Bottle Song

Bowling

Change

Circular Buffer

Complex Numbers

Connect

Custom Set

D&D Character

DOT DSL

Darts

Diamond

Dominoes

Error Handling

Food Chain

Forth

Go Counting

Grep

Hangman

High Scores

House

ISBN Verifier

Killer Sudoku Helper

Kindergarten Garden

Knapsack

Ledger

Lens Person

Linked List

List Ops

Markdown

Matrix

Micro Blog

Minesweeper

OCR Numbers

POV

PaaS I/O

Palindrome Products

Parallel Letter Frequency

Pig Latin

Poker

Protein Translation

Proverb

Pythagorean Triplet

Queen Attack

REST API

Rail Fence Cipher

Rational Numbers

React

Rectangles

Resistor Color

Resistor Color Duo

Resistor Color Trio

Robot Simulator

Rotational Cipher

SGF Parsing

Saddle Points

Satellite

Scale Generator

Simple Cipher

Simple Linked List

Spiral Matrix

Square Root

State of Tic-Tac-Toe

Tournament

Tree Building

Twelve Days

Two Bucket

Variable Length Quantity

Word Search

Wordy

Yacht

Zebra Puzzle

Zipper

Volunteers

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