Kotlin

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students have developed their Kotlin skills on Exercism.

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25,048

Submissions

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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 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

10,628

8,942 (avg. 0.8)

7,680 (72.3%)

13 (0.1%)

Two Fer

5,705

6,895 (avg. 1.2)

4,453 (78.1%)

1,523 (26.7%)

Hamming

3,639

5,070 (avg. 1.4)

2,890 (79.4%)

804 (22.1%)

Gigasecond

2,695

3,333 (avg. 1.2)

2,155 (80.0%)

462 (17.1%)

Scrabble Score

2,069

2,877 (avg. 1.4)

1,811 (87.5%)

371 (17.9%)

Matrix

1,206

1,434 (avg. 1.2)

899 (74.5%)

142 (11.8%)

Difference of Squares

1,489

2,072 (avg. 1.4)

1,300 (87.3%)

239 (16.1%)

Secret Handshake

1,233

1,587 (avg. 1.3)

971 (78.8%)

197 (16.0%)

Triangle

1,020

1,450 (avg. 1.4)

837 (82.1%)

161 (15.8%)

Saddle Points

725

862 (avg. 1.2)

513 (70.8%)

109 (15.0%)

Flatten Array

766

951 (avg. 1.2)

619 (80.8%)

84 (11.0%)

Word Count

739

954 (avg. 1.3)

581 (78.6%)

72 (9.7%)

Robot Name

556

752 (avg. 1.4)

432 (77.7%)

71 (12.8%)

Rotational Cipher

396

517 (avg. 1.3)

335 (84.6%)

56 (14.1%)

Bank Account

499

601 (avg. 1.2)

380 (76.2%)

62 (12.4%)

Linked List

423

500 (avg. 1.2)

319 (75.4%)

44 (10.4%)

Binary Search

362

412 (avg. 1.1)

280 (77.3%)

39 (10.8%)

Pangram

2,321

2,902 (avg. 1.3)

1,823 (78.5%)

92 (4.0%)

Raindrops

1,518

1,866 (avg. 1.2)

1,234 (81.3%)

66 (4.3%)

Isogram

1,051

1,290 (avg. 1.2)

854 (81.3%)

51 (4.9%)

Pig Latin

775

692 (avg. 0.9)

449 (57.9%)

23 (3.0%)

Anagram

830

932 (avg. 1.1)

612 (73.7%)

35 (4.2%)

Resistor Color

890

986 (avg. 1.1)

740 (83.1%)

12 (1.3%)

Resistor Color Duo

786

939 (avg. 1.2)

646 (82.2%)

8 (1.0%)

RNA Transcription

1,897

2,318 (avg. 1.2)

1,628 (85.8%)

67 (3.5%)

Diamond

613

700 (avg. 1.1)

428 (69.8%)

21 (3.4%)

Bob

546

607 (avg. 1.1)

417 (76.4%)

15 (2.7%)

Beer Song

455

480 (avg. 1.1)

334 (73.4%)

17 (3.7%)

Acronym

1,069

1,287 (avg. 1.2)

900 (84.2%)

23 (2.2%)

Armstrong Numbers

298

342 (avg. 1.1)

253 (84.9%)

5 (1.7%)

Resistor Color Trio

605

676 (avg. 1.1)

436 (72.1%)

5 (0.8%)

Transpose

542

481 (avg. 0.9)

287 (53.0%)

4 (0.7%)

ISBN Verifier

311

333 (avg. 1.1)

228 (73.3%)

4 (1.3%)

Largest Series Product

590

797 (avg. 1.4)

447 (75.8%)

11 (1.9%)

Luhn

700

833 (avg. 1.2)

515 (73.6%)

12 (1.7%)

Nucleotide Count

414

496 (avg. 1.2)

328 (79.2%)

11 (2.7%)

Phone Number

411

476 (avg. 1.2)

320 (77.9%)

8 (1.9%)

Series

323

363 (avg. 1.1)

260 (80.5%)

8 (2.5%)

Roman Numerals

349

354 (avg. 1.0)

250 (71.6%)

8 (2.3%)

Leap

1,174

1,323 (avg. 1.1)

891 (75.9%)

36 (3.1%)

Custom Set

361

349 (avg. 1.0)

237 (65.7%)

4 (1.1%)

Space Age

893

1,105 (avg. 1.2)

739 (82.8%)

15 (1.7%)

Allergies

353

401 (avg. 1.1)

257 (72.8%)

3 (0.8%)

Meetup

211

182 (avg. 0.9)

128 (60.7%)

0 (0.0%)

Crypto Square

225

224 (avg. 1.0)

137 (60.9%)

2 (0.9%)

Run-Length Encoding

288

305 (avg. 1.1)

196 (68.1%)

3 (1.0%)

Scale Generator

207

159 (avg. 0.8)

111 (53.6%)

0 (0.0%)

Wordy

224

230 (avg. 1.0)

132 (58.9%)

4 (1.8%)

Minesweeper

286

264 (avg. 0.9)

170 (59.4%)

4 (1.4%)

Dominoes

117

89 (avg. 0.8)

53 (45.3%)

2 (1.7%)

Perfect Numbers

543

711 (avg. 1.3)

452 (83.2%)

11 (2.0%)

Yacht

184

200 (avg. 1.1)

137 (74.5%)

1 (0.5%)

Sieve

387

465 (avg. 1.2)

303 (78.3%)

3 (0.8%)

Sum of Multiples

588

677 (avg. 1.2)

438 (74.5%)

7 (1.2%)

Forth

183

158 (avg. 0.9)

95 (51.9%)

6 (3.3%)

Grains

404

515 (avg. 1.3)

321 (79.5%)

6 (1.5%)

Robot Simulator

196

222 (avg. 1.1)

132 (67.3%)

2 (1.0%)

Collatz Conjecture

364

432 (avg. 1.2)

291 (79.9%)

9 (2.5%)

Kindergarten Garden

130

136 (avg. 1.0)

92 (70.8%)

1 (0.8%)

Nth Prime

331

384 (avg. 1.2)

257 (77.6%)

4 (1.2%)

Pascal's Triangle

196

203 (avg. 1.0)

144 (73.5%)

1 (0.5%)

Prime Factors

184

181 (avg. 1.0)

127 (69.0%)

0 (0.0%)

Complex Numbers

206

194 (avg. 0.9)

129 (62.6%)

5 (2.4%)

All Your Base

160

163 (avg. 1.0)

104 (65.0%)

0 (0.0%)

Clock

159

176 (avg. 1.1)

108 (67.9%)

0 (0.0%)

Matching Brackets

212

227 (avg. 1.1)

154 (72.6%)

4 (1.9%)

Spiral Matrix

195

184 (avg. 0.9)

128 (65.6%)

1 (0.5%)

Change

267

212 (avg. 0.8)

118 (44.2%)

8 (3.0%)

Binary Search Tree

108

89 (avg. 0.8)

60 (55.6%)

0 (0.0%)

ETL

274

322 (avg. 1.2)

224 (81.8%)

4 (1.5%)

Grade School

198

217 (avg. 1.1)

144 (72.7%)

5 (2.5%)

Affine Cipher

101 (avg. 1.1)

59 (62.1%)

0 (0.0%)

Atbash Cipher

308

393 (avg. 1.3)

247 (80.2%)

2 (0.6%)

Rail Fence Cipher

157

134 (avg. 0.9)

88 (56.1%)

1 (0.6%)

Say

133

124 (avg. 0.9)

80 (60.2%)

1 (0.8%)

Simple Cipher

177

160 (avg. 0.9)

99 (55.9%)

0 (0.0%)

Sublist

153

136 (avg. 0.9)

95 (62.1%)

0 (0.0%)

Diffie-Hellman

121

103 (avg. 0.9)

68 (56.2%)

1 (0.8%)

List Ops

224

170 (avg. 0.8)

113 (50.4%)

1 (0.4%)

Zebra Puzzle

114

74 (avg. 0.6)

38 (33.3%)

1 (0.9%)

React

233

171 (avg. 0.7)

92 (39.5%)

4 (1.7%)

D&D Character

915

945 (avg. 1.0)

563 (61.5%)

10 (1.1%)

Reverse String

1,768

1,695 (avg. 1.0)

1,271 (71.9%)

15 (0.8%)

Darts

438

501 (avg. 1.1)

323 (73.7%)

3 (0.7%)

Knapsack

38 (avg. 0.8)

24 (52.2%)

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

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Word Search

View data

Zipper

View data

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25,048 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

25,048
students have developed their Kotlin skills on Exercism.