Objective-C

1,782 students

29 contributors

1,782
students have developed their Objective-C skills on Exercism.

Students

1,782

Submissions

1,828

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

513

372 (avg. 0.7)

265 (51.7%)

0 (0.0%)

Bob

237

289 (avg. 1.2)

189 (79.7%)

21 (8.9%)

Difference of Squares

60

66 (avg. 1.1)

43 (71.7%)

5 (8.3%)

Gigasecond

55

59 (avg. 1.1)

43 (78.2%)

3 (5.5%)

Leap

80

87 (avg. 1.1)

64 (80.0%)

5 (6.3%)

Reverse String

41

39 (avg. 1.0)

27 (65.9%)

1 (2.4%)

Space Age

39

35 (avg. 0.9)

30 (76.9%)

1 (2.6%)

Sum of Multiples

44

48 (avg. 1.1)

32 (72.7%)

1 (2.3%)

Two Fer

106

101 (avg. 1.0)

57 (53.8%)

27 (25.5%)

ETL

33

32 (avg. 1.0)

25 (75.8%)

0 (0.0%)

Flatten Array

22

25 (avg. 1.1)

15 (68.2%)

0 (0.0%)

Grade School

42

43 (avg. 1.0)

31 (73.8%)

0 (0.0%)

Hamming

92

108 (avg. 1.2)

84 (91.3%)

4 (4.3%)

Isogram

19

24 (avg. 1.3)

14 (73.7%)

0 (0.0%)

Nucleotide Count

43

49 (avg. 1.1)

37 (86.0%)

3 (7.0%)

Prime Factors

18

14 (avg. 0.8)

10 (55.6%)

0 (0.0%)

Raindrops

39

37 (avg. 0.9)

26 (66.7%)

3 (7.7%)

RNA Transcription

11

12 (avg. 1.1)

7 (63.6%)

0 (0.0%)

Atbash Cipher

12

12 (avg. 1.0)

8 (66.7%)

0 (0.0%)

Clock

14

12 (avg. 0.9)

8 (57.1%)

0 (0.0%)

Collatz Conjecture

9

8 (avg. 0.9)

5 (55.6%)

0 (0.0%)

Grains

9

8 (avg. 0.9)

6 (66.7%)

0 (0.0%)

Perfect Numbers

12

9 (avg. 0.8)

8 (66.7%)

0 (0.0%)

Phone Number

27

28 (avg. 1.0)

24 (88.9%)

1 (3.7%)

Robot Name

28

28 (avg. 1.0)

21 (75.0%)

0 (0.0%)

Scrabble Score

14

11 (avg. 0.8)

8 (57.1%)

0 (0.0%)

Secret Handshake

9

7 (avg. 0.8)

5 (55.6%)

0 (0.0%)

Series

9

3 (avg. 0.3)

3 (33.3%)

0 (0.0%)

Sieve

9

6 (avg. 0.7)

5 (55.6%)

0 (0.0%)

Strain

9

6 (avg. 0.7)

5 (55.6%)

0 (0.0%)

Sublist

16

14 (avg. 0.9)

10 (62.5%)

0 (0.0%)

Triangle

14

8 (avg. 0.6)

7 (50.0%)

0 (0.0%)

Acronym

12

10 (avg. 0.8)

7 (58.3%)

0 (0.0%)

All Your Base

14

9 (avg. 0.6)

9 (64.3%)

0 (0.0%)

Allergies

11

11 (avg. 1.0)

7 (63.6%)

0 (0.0%)

Anagram

40

49 (avg. 1.2)

36 (90.0%)

1 (2.5%)

Beer Song

13

11 (avg. 0.8)

9 (69.2%)

0 (0.0%)

Binary Search

9

8 (avg. 0.9)

4 (44.4%)

0 (0.0%)

Crypto Square

8

3 (avg. 0.4)

3 (37.5%)

0 (0.0%)

Largest Series Product

9

6 (avg. 0.7)

5 (55.6%)

0 (0.0%)

Meetup

10

7 (avg. 0.7)

4 (40.0%)

0 (0.0%)

Nth Prime

9

7 (avg. 0.8)

4 (44.4%)

0 (0.0%)

Pangram

11

5 (avg. 0.5)

5 (45.5%)

0 (0.0%)

Pascal's Triangle

8

7 (avg. 0.9)

4 (50.0%)

0 (0.0%)

Say

6

2 (avg. 0.3)

2 (33.3%)

0 (0.0%)

Transpose

7

3 (avg. 0.4)

3 (42.9%)

0 (0.0%)

Word Count

52

65 (avg. 1.3)

48 (92.3%)

2 (3.8%)

Matching Brackets

9

7 (avg. 0.8)

4 (44.4%)

0 (0.0%)

Luhn

12

9 (avg. 0.8)

5 (41.7%)

0 (0.0%)

Roman Numerals

7

4 (avg. 0.6)

4 (57.1%)

0 (0.0%)

Run-Length Encoding

11

5 (avg. 0.5)

5 (45.5%)

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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