Kotlin

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25,416
students have developed their Kotlin skills on Exercism.

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25,416

Submissions

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5,145

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Build Test Runners

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

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Build Analyzers

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

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

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Create Practice Exercises

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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

85 active practice exercises

Started

Attempts

Completions

Mentoring requests

Hello World

10,781

9,066 (avg. 0.8)

7,794 (72.3%)

13 (0.1%)

Two Fer

5,781

6,977 (avg. 1.2)

4,517 (78.1%)

1,527 (26.4%)

Hamming

3,701

5,148 (avg. 1.4)

2,940 (79.4%)

808 (21.8%)

Gigasecond

2,738

3,376 (avg. 1.2)

2,187 (79.9%)

463 (16.9%)

Scrabble Score

2,108

2,926 (avg. 1.4)

1,845 (87.5%)

373 (17.7%)

Matrix

1,244

1,487 (avg. 1.2)

933 (75.0%)

143 (11.5%)

Difference of Squares

1,509

2,097 (avg. 1.4)

1,319 (87.4%)

240 (15.9%)

Secret Handshake

1,252

1,605 (avg. 1.3)

987 (78.8%)

197 (15.7%)

Triangle

1,039

1,473 (avg. 1.4)

854 (82.2%)

161 (15.5%)

Saddle Points

741

885 (avg. 1.2)

525 (70.9%)

110 (14.8%)

Flatten Array

789

978 (avg. 1.2)

641 (81.2%)

84 (10.6%)

Word Count

756

970 (avg. 1.3)

592 (78.3%)

73 (9.7%)

Robot Name

573

776 (avg. 1.4)

446 (77.8%)

71 (12.4%)

Rotational Cipher

406

531 (avg. 1.3)

344 (84.7%)

56 (13.8%)

Bank Account

514

623 (avg. 1.2)

394 (76.7%)

64 (12.5%)

Linked List

432

511 (avg. 1.2)

328 (75.9%)

44 (10.2%)

Binary Search

377

429 (avg. 1.1)

292 (77.5%)

39 (10.3%)

Pangram

2,334

2,918 (avg. 1.3)

1,834 (78.6%)

94 (4.0%)

Raindrops

1,528

1,875 (avg. 1.2)

1,242 (81.3%)

66 (4.3%)

Isogram

1,061

1,299 (avg. 1.2)

862 (81.2%)

51 (4.8%)

Pig Latin

780

697 (avg. 0.9)

453 (58.1%)

23 (2.9%)

Anagram

835

937 (avg. 1.1)

616 (73.8%)

35 (4.2%)

Resistor Color

896

992 (avg. 1.1)

745 (83.1%)

12 (1.3%)

Resistor Color Duo

790

944 (avg. 1.2)

650 (82.3%)

8 (1.0%)

RNA Transcription

1,909

2,333 (avg. 1.2)

1,640 (85.9%)

67 (3.5%)

Diamond

617

704 (avg. 1.1)

432 (70.0%)

21 (3.4%)

Bob

549

613 (avg. 1.1)

421 (76.7%)

15 (2.7%)

Beer Song

457

485 (avg. 1.1)

337 (73.7%)

17 (3.7%)

Acronym

1,079

1,299 (avg. 1.2)

911 (84.4%)

23 (2.1%)

Armstrong Numbers

304

347 (avg. 1.1)

257 (84.5%)

5 (1.6%)

Resistor Color Trio

606

679 (avg. 1.1)

438 (72.3%)

5 (0.8%)

Transpose

546

483 (avg. 0.9)

288 (52.7%)

4 (0.7%)

ISBN Verifier

319

342 (avg. 1.1)

237 (74.3%)

4 (1.3%)

Largest Series Product

593

801 (avg. 1.4)

450 (75.9%)

11 (1.9%)

Luhn

706

840 (avg. 1.2)

521 (73.8%)

12 (1.7%)

Nucleotide Count

421

509 (avg. 1.2)

336 (79.8%)

11 (2.6%)

Phone Number

417

484 (avg. 1.2)

326 (78.2%)

8 (1.9%)

Series

324

365 (avg. 1.1)

262 (80.9%)

8 (2.5%)

Roman Numerals

350

357 (avg. 1.0)

253 (72.3%)

8 (2.3%)

Leap

1,177

1,327 (avg. 1.1)

895 (76.0%)

36 (3.1%)

Custom Set

368

354 (avg. 1.0)

241 (65.5%)

4 (1.1%)

Space Age

895

1,108 (avg. 1.2)

741 (82.8%)

15 (1.7%)

Allergies

356

405 (avg. 1.1)

260 (73.0%)

3 (0.8%)

Meetup

213

185 (avg. 0.9)

130 (61.0%)

0 (0.0%)

Crypto Square

228

227 (avg. 1.0)

140 (61.4%)

2 (0.9%)

Run-Length Encoding

293

310 (avg. 1.1)

200 (68.3%)

3 (1.0%)

Scale Generator

209

163 (avg. 0.8)

114 (54.5%)

0 (0.0%)

Wordy

225

232 (avg. 1.0)

134 (59.6%)

4 (1.8%)

Minesweeper

288

267 (avg. 0.9)

173 (60.1%)

4 (1.4%)

Dominoes

118

91 (avg. 0.8)

55 (46.6%)

2 (1.7%)

Perfect Numbers

544

713 (avg. 1.3)

454 (83.5%)

11 (2.0%)

Yacht

185

201 (avg. 1.1)

138 (74.6%)

1 (0.5%)

Sieve

388

469 (avg. 1.2)

305 (78.6%)

3 (0.8%)

Sum of Multiples

588

678 (avg. 1.2)

439 (74.7%)

7 (1.2%)

Forth

185

160 (avg. 0.9)

97 (52.4%)

6 (3.2%)

Grains

405

517 (avg. 1.3)

323 (79.8%)

6 (1.5%)

Robot Simulator

198

224 (avg. 1.1)

134 (67.7%)

2 (1.0%)

Collatz Conjecture

365

433 (avg. 1.2)

292 (80.0%)

9 (2.5%)

Kindergarten Garden

131

138 (avg. 1.1)

94 (71.8%)

1 (0.8%)

Nth Prime

332

386 (avg. 1.2)

259 (78.0%)

4 (1.2%)

Pascal's Triangle

197

205 (avg. 1.0)

146 (74.1%)

1 (0.5%)

Prime Factors

185

183 (avg. 1.0)

129 (69.7%)

0 (0.0%)

Complex Numbers

209

197 (avg. 0.9)

131 (62.7%)

5 (2.4%)

All Your Base

162

165 (avg. 1.0)

106 (65.4%)

0 (0.0%)

Clock

160

177 (avg. 1.1)

109 (68.1%)

0 (0.0%)

Matching Brackets

213

229 (avg. 1.1)

156 (73.2%)

4 (1.9%)

Spiral Matrix

196

186 (avg. 0.9)

130 (66.3%)

1 (0.5%)

Change

269

214 (avg. 0.8)

120 (44.6%)

8 (3.0%)

Binary Search Tree

109

91 (avg. 0.8)

62 (56.9%)

0 (0.0%)

ETL

276

325 (avg. 1.2)

227 (82.2%)

4 (1.4%)

Grade School

200

220 (avg. 1.1)

147 (73.5%)

5 (2.5%)

Affine Cipher

102 (avg. 1.1)

60 (62.5%)

0 (0.0%)

Atbash Cipher

308

394 (avg. 1.3)

248 (80.5%)

2 (0.6%)

Rail Fence Cipher

158

136 (avg. 0.9)

90 (57.0%)

1 (0.6%)

Say

136

129 (avg. 0.9)

83 (61.0%)

1 (0.7%)

Simple Cipher

179

165 (avg. 0.9)

101 (56.4%)

1 (0.6%)

Sublist

159

142 (avg. 0.9)

100 (62.9%)

0 (0.0%)

Diffie-Hellman

126

107 (avg. 0.8)

72 (57.1%)

1 (0.8%)

List Ops

227

171 (avg. 0.8)

114 (50.2%)

1 (0.4%)

Zebra Puzzle

117

76 (avg. 0.6)

40 (34.2%)

1 (0.9%)

React

236

176 (avg. 0.7)

94 (39.8%)

5 (2.1%)

D&D Character

920

952 (avg. 1.0)

568 (61.7%)

10 (1.1%)

Reverse String

1,770

1,698 (avg. 1.0)

1,274 (72.0%)

15 (0.8%)

Darts

440

503 (avg. 1.1)

325 (73.9%)

3 (0.7%)

Knapsack

40 (avg. 0.8)

26 (53.1%)

0 (0.0%)

4 deprecated practice exercises

Started

Attempts

Completions

Mentoring requests

Accumulate

117 (avg. 1.4)

83 (96.5%)

7 (8.1%)

Binary

46 (avg. 1.4)

32 (94.1%)

0 (0.0%)

Hexadecimal

29 (avg. 1.1)

25 (96.2%)

1 (3.8%)

Strain

36 (avg. 1.3)

27 (96.4%)

0 (0.0%)

44 unimplemented practice exercises

Alphametics

Book Store

Bottle Song

Bowling

Circular Buffer

Connect

DOT DSL

Error Handling

Food Chain

Go Counting

Grep

Hangman

High Scores

House

Killer Sudoku Helper

Ledger

Lens Person

Markdown

Micro Blog

OCR Numbers

POV

PaaS I/O

Palindrome Products

Parallel Letter Frequency

Poker

Protein Translation

Proverb

Pythagorean Triplet

Queen Attack

REST API

Rational Numbers

Rectangles

SGF Parsing

Satellite

Simple Linked List

Square Root

State of Tic-Tac-Toe

Tournament

Tree Building

Twelve Days

Two Bucket

Variable Length Quantity

View data

Word Search

View data

Zipper

View data

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2,505

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1,781

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25,416 students have developed their Kotlin skills on Exercism.

The Kotlin track needs attention ⚠️

Build

Build Test Runners

Build Analyzers

Build Representers

Create Practice Exercises

Usage statistics

We 💙 our volunteers

25,416
students have developed their Kotlin skills on Exercism.