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Java Track Management

This page provides the Exercism community with the information and tools needed to manage the Java track.

Students
211,505
Submissions
3,356,980
Mentoring Discussions
16,312

The Java track is healthy ✅

Building

Java syllabus

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Help create the track syllabus: is a set of concepts and learning exercises put together to teach foundational elements of the programming language.

Next goal: Create a complete syllabus with at least 30 concepts. Find out more.
26 concepts being taught
Ba
Basics
42,973 learnt
Bo
Booleans
24,337 learnt
Ar
Arrays
11,369 learnt
Fo
For Loops
11,369 learnt
Fo
For-Each Loops
11,369 learnt
Ge
Generic Types
8,067 learnt
Li
Lists
8,067 learnt
Ex
Exceptions
3,383 learnt
Ch
Chars
7,782 learnt
Cl
Classes
7,535 learnt
Co
Constructors
5,574 learnt
In
Interfaces
4,148 learnt
If
If-Else Statements
11,973 learnt
Nu
Numbers
11,973 learnt
St
Strings
16,538 learnt
Te
Ternary Operators
6,672 learnt
Sw
Switch Statements
4,879 learnt
In
Inheritance
4,423 learnt
En
Enums
2,202 learnt
Nu
Nullability
3,561 learnt
Ra
Randomness
2,411 learnt
Da
Date-Time
2,445 learnt
Me
Method Overloading
1,814 learnt
Bi
Bit Manipulation
2,141 learnt
Se
Sets
1,567 learnt
Ma
Maps
363 learnt
22 active learning exercises
Started
Attempts
Completions
Mentoring requests
Cook Your Lasagna Cook Your Lasagna
70,128
385,926 (avg. 5.5)
42,973 (61.3%)
466 (0.7%)
Annalyn's Infiltration Annalyn's Infiltration
32,609
308,890 (avg. 9.5)
24,337 (74.6%)
302 (0.9%)
Bird Watcher Bird Watcher
13,630
187,734 (avg. 13.8)
11,369 (83.4%)
249 (1.8%)
Karl's Languages Karl's Languages
8,826
48,569 (avg. 5.5)
8,067 (91.4%)
67 (0.8%)
Calculator Conundrum Calculator Conundrum
4,122
57,392 (avg. 13.9)
3,383 (82.1%)
64 (1.6%)
Squeaky Clean Squeaky Clean
12,380
190,351 (avg. 15.4)
7,782 (62.9%)
366 (3.0%)
Jedlik's Toy Car Jedlik's Toy Car
8,223
69,248 (avg. 8.4)
7,535 (91.6%)
88 (1.1%)
Need for Speed Need for Speed
6,327
75,731 (avg. 12.0)
5,574 (88.1%)
63 (1.0%)
Remote Control Competition Remote Control Competition
5,241
57,323 (avg. 10.9)
4,148 (79.1%)
76 (1.5%)
Cars, Assemble! Cars, Assemble!
13,350
102,190 (avg. 7.7)
11,973 (89.7%)
240 (1.8%)
Log Levels Log Levels
25,824
233,413 (avg. 9.0)
16,538 (64.0%)
281 (1.1%)
Salary Calculator Salary Calculator
7,171
41,846 (avg. 5.8)
6,672 (93.0%)
38 (0.5%)
Football Match Reports Football Match Reports
5,029
21,228 (avg. 4.2)
4,879 (97.0%)
36 (0.7%)
Wizards and Warriors Wizards and Warriors
4,861
33,682 (avg. 6.9)
4,423 (91.0%)
35 (0.7%)
Logs, Logs, Logs! Logs, Logs, Logs!
2,582
26,545 (avg. 10.3)
2,202 (85.3%)
33 (1.3%)
Tim from Marketing Tim from Marketing
3,785
25,581 (avg. 6.8)
3,561 (94.1%)
52 (1.4%)
Captain's Log Captain's Log
2,574
16,680 (avg. 6.5)
2,411 (93.7%)
13 (0.5%)
Booking Up For Beauty Booking Up For Beauty
2,968
42,576 (avg. 14.3)
2,445 (82.4%)
25 (0.8%)
Wizards and Warriors 2 Wizards and Warriors 2
1,998
17,115 (avg. 8.6)
1,814 (90.8%)
17 (0.9%)
Secrets Secrets
2,485
14,154 (avg. 5.7)
2,141 (86.2%)
4 (0.2%)
Gotta Snatch 'Em All Gotta Snatch 'Em All
1,875
23,741 (avg. 12.7)
1,567 (83.6%)
26 (1.4%)
International Calling Connoisseur International Calling Connoisseur
433
4,599 (avg. 10.6)
363 (83.8%)
3 (0.7%)
1 deprecated learning exercises
Started
Attempts
Completions
Mentoring requests
Play Your Cards! Play Your Cards!
8,676
85,880 (avg. 9.9)
6,855 (79.0%)
121 (1.4%)

Practice Exercises

Learn More

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.

Synced primary repo: df966c341a9530ae2289613b6a0ccac32cdfbbc6 (Updates should be instant)

Next goal: Implement 133 practice exercises. Find out more.
127 active practice exercises
Started
Attempts
Completions
Mentoring requests
Hello World Hello World
155,341
323,395 (avg. 2.1)
99,245 (63.9%)
40 (0.0%)
Leap Leap
5,813
19,441 (avg. 3.3)
4,724 (81.3%)
88 (1.5%)
Reverse String Reverse String
14,080
41,433 (avg. 2.9)
11,743 (83.4%)
316 (2.2%)
Two Fer Two Fer
22,356
70,730 (avg. 3.2)
17,648 (78.9%)
3,919 (17.5%)
Armstrong Numbers Armstrong Numbers
5,770
17,466 (avg. 3.0)
4,515 (78.2%)
127 (2.2%)
Darts Darts
5,897
20,055 (avg. 3.4)
4,588 (77.8%)
59 (1.0%)
D&D Character D&D Character
3,897
29,374 (avg. 7.5)
2,710 (69.5%)
61 (1.6%)
DOT DSL DOT DSL
609
2,837 (avg. 4.7)
364 (59.8%)
4 (0.7%)
Grains Grains
3,811
28,832 (avg. 7.6)
3,065 (80.4%)
47 (1.2%)
High Scores High Scores
1,686
14,372 (avg. 8.5)
1,366 (81.0%)
31 (1.8%)
Resistor Color Resistor Color
5,764
20,155 (avg. 3.5)
4,576 (79.4%)
67 (1.2%)
Resistor Color Duo Resistor Color Duo
3,950
12,263 (avg. 3.1)
3,303 (83.6%)
40 (1.0%)
Resistor Color Trio Resistor Color Trio
989
11,980 (avg. 12.1)
838 (84.7%)
28 (2.8%)
RNA Transcription RNA Transcription
6,033
14,794 (avg. 2.5)
5,067 (84.0%)
232 (3.8%)
Acronym Acronym
3,952
15,069 (avg. 3.8)
3,127 (79.1%)
88 (2.2%)
Difference of Squares Difference of Squares
6,266
21,100 (avg. 3.4)
5,458 (87.1%)
705 (11.3%)
Gigasecond Gigasecond
8,077
18,867 (avg. 2.3)
5,737 (71.0%)
1,343 (16.6%)
Hamming Hamming
7,981
29,006 (avg. 3.6)
6,559 (82.2%)
1,489 (18.7%)
Micro Blog Micro Blog
5,980
34,382 (avg. 5.7)
3,605 (60.3%)
84 (1.4%)
Pangram Pangram
4,945
12,034 (avg. 2.4)
4,097 (82.9%)
168 (3.4%)
Perfect Numbers Perfect Numbers
3,152
11,498 (avg. 3.6)
2,131 (67.6%)
41 (1.3%)
Eliud's Eggs Eliud's Eggs
768
2,611 (avg. 3.4)
687 (89.5%)
7 (0.9%)
Protein Translation Protein Translation
3,209
13,861 (avg. 4.3)
2,518 (78.5%)
47 (1.5%)
Raindrops Raindrops
7,702
19,863 (avg. 2.6)
6,464 (83.9%)
250 (3.2%)
Say Say
2,188
13,159 (avg. 6.0)
873 (39.9%)
34 (1.6%)
Scrabble Score Scrabble Score
5,839
21,197 (avg. 3.6)
4,928 (84.4%)
1,080 (18.5%)
Secret Handshake Secret Handshake
3,864
18,478 (avg. 4.8)
2,939 (76.1%)
464 (12.0%)
Space Age Space Age
4,001
8,468 (avg. 2.1)
3,070 (76.7%)
60 (1.5%)
Collatz Conjecture Collatz Conjecture
1,573
5,818 (avg. 3.7)
1,303 (82.8%)
27 (1.7%)
Diamond Diamond
2,349
11,210 (avg. 4.8)
1,547 (65.9%)
46 (2.0%)
Error Handling Error Handling
1,506
10,743 (avg. 7.1)
839 (55.7%)
5 (0.3%)
ISBN Verifier ISBN Verifier
2,372
10,131 (avg. 4.3)
1,842 (77.7%)
39 (1.6%)
Isogram Isogram
4,716
17,432 (avg. 3.7)
3,791 (80.4%)
166 (3.5%)
Killer Sudoku Helper Killer Sudoku Helper
468
2,652 (avg. 5.7)
261 (55.8%)
11 (2.4%)
Kindergarten Garden Kindergarten Garden
1,050
2,962 (avg. 2.8)
764 (72.8%)
9 (0.9%)
Largest Series Product Largest Series Product
1,694
9,098 (avg. 5.4)
1,342 (79.2%)
19 (1.1%)
Luhn Luhn
2,333
10,719 (avg. 4.6)
1,809 (77.5%)
48 (2.1%)
Matrix Matrix
3,025
15,136 (avg. 5.0)
2,281 (75.4%)
312 (10.3%)
Nth Prime Nth Prime
1,279
4,385 (avg. 3.4)
980 (76.6%)
15 (1.2%)
Proverb Proverb
2,642
7,478 (avg. 2.8)
2,133 (80.7%)
32 (1.2%)
Rotational Cipher Rotational Cipher
2,288
11,345 (avg. 5.0)
1,926 (84.2%)
224 (9.8%)
Saddle Points Saddle Points
1,683
7,182 (avg. 4.3)
1,143 (67.9%)
160 (9.5%)
Sieve Sieve
1,314
3,482 (avg. 2.6)
1,048 (79.8%)
23 (1.8%)
Sum of Multiples Sum of Multiples
1,900
6,401 (avg. 3.4)
1,376 (72.4%)
35 (1.8%)
Triangle Triangle
2,739
10,837 (avg. 4.0)
2,335 (85.3%)
258 (9.4%)
Twelve Days Twelve Days
2,563
13,724 (avg. 5.4)
1,928 (75.2%)
33 (1.3%)
Variable Length Quantity Variable Length Quantity
589
1,840 (avg. 3.1)
297 (50.4%)
1 (0.2%)
Yacht Yacht
1,491
6,539 (avg. 4.4)
981 (65.8%)
29 (1.9%)
Allergies Allergies
1,200
3,985 (avg. 3.3)
925 (77.1%)
25 (2.1%)
Atbash Cipher Atbash Cipher
721
3,675 (avg. 5.1)
569 (78.9%)
7 (1.0%)
Bob Bob
1,971
11,258 (avg. 5.7)
1,611 (81.7%)
58 (2.9%)
Flatten Array Flatten Array
1,620
7,205 (avg. 4.4)
1,219 (75.2%)
135 (8.3%)
Conway's Game of Life Conway's Game of Life
245
970 (avg. 4.0)
135 (55.1%)
0 (0.0%)
Grep Grep
607
2,514 (avg. 4.1)
323 (53.2%)
5 (0.8%)
Knapsack Knapsack
847
3,809 (avg. 4.5)
501 (59.1%)
9 (1.1%)
Ledger Ledger
287
1,831 (avg. 6.4)
154 (53.7%)
6 (2.1%)
Matching Brackets Matching Brackets
702
2,515 (avg. 3.6)
503 (71.7%)
8 (1.1%)
Nucleotide Count Nucleotide Count
2,042
5,798 (avg. 2.8)
1,827 (89.5%)
89 (4.4%)
Pascal's Triangle Pascal's Triangle
725
1,803 (avg. 2.5)
505 (69.7%)
4 (0.6%)
Phone Number Phone Number
1,406
7,245 (avg. 5.2)
1,088 (77.4%)
24 (1.7%)
Pig Latin Pig Latin
2,629
10,860 (avg. 4.1)
1,444 (54.9%)
76 (2.9%)
Prime Factors Prime Factors
812
2,432 (avg. 3.0)
612 (75.4%)
11 (1.4%)
Robot Name Robot Name
1,712
9,629 (avg. 5.6)
1,424 (83.2%)
137 (8.0%)
Run-Length Encoding Run-Length Encoding
587
2,187 (avg. 3.7)
411 (70.0%)
9 (1.5%)
Series Series
930
2,553 (avg. 2.7)
763 (82.0%)
11 (1.2%)
Square Root Square Root
419
1,237 (avg. 3.0)
331 (79.0%)
7 (1.7%)
Word Count Word Count
2,752
15,845 (avg. 5.8)
2,108 (76.6%)
212 (7.7%)
State Of Tic Tac Toe State Of Tic Tac Toe
196
1,324 (avg. 6.8)
115 (58.7%)
5 (2.6%)
Affine Cipher Affine Cipher
314
2,142 (avg. 6.8)
199 (63.4%)
3 (1.0%)
All Your Base All Your Base
449
2,082 (avg. 4.6)
298 (66.4%)
2 (0.4%)
Alphametics Alphametics
498
1,880 (avg. 3.8)
190 (38.2%)
3 (0.6%)
Bank Account Bank Account
1,492
8,215 (avg. 5.5)
1,066 (71.4%)
89 (6.0%)
Binary Search Binary Search
1,232
6,829 (avg. 5.5)
934 (75.8%)
93 (7.5%)
Bottle Song Bottle Song
622
6,048 (avg. 9.7)
402 (64.6%)
18 (2.9%)
Bowling Bowling
858
6,230 (avg. 7.3)
378 (44.1%)
11 (1.3%)
ETL ETL
1,736
2,529 (avg. 1.5)
1,591 (91.6%)
128 (7.4%)
Food Chain Food Chain
820
3,002 (avg. 3.7)
553 (67.4%)
10 (1.2%)
Grade School Grade School
742
2,348 (avg. 3.2)
545 (73.5%)
21 (2.8%)
House House
892
3,276 (avg. 3.7)
654 (73.3%)
9 (1.0%)
Linked List Linked List
1,315
5,545 (avg. 4.2)
941 (71.6%)
75 (5.7%)
Minesweeper Minesweeper
779
2,726 (avg. 3.5)
507 (65.1%)
9 (1.2%)
Parallel Letter Frequency Parallel Letter Frequency
672
3,060 (avg. 4.6)
420 (62.5%)
12 (1.8%)
Queen Attack Queen Attack
1,979
7,446 (avg. 3.8)
716 (36.2%)
33 (1.7%)
Rail Fence Cipher Rail Fence Cipher
321
1,251 (avg. 3.9)
189 (58.9%)
1 (0.3%)
REST API REST API
601
2,607 (avg. 4.3)
140 (23.3%)
4 (0.7%)
Robot Simulator Robot Simulator
737
2,306 (avg. 3.1)
465 (63.1%)
10 (1.4%)
Roman Numerals Roman Numerals
1,096
3,274 (avg. 3.0)
814 (74.3%)
15 (1.4%)
Spiral Matrix Spiral Matrix
532
1,263 (avg. 2.4)
325 (61.1%)
6 (1.1%)
Tournament Tournament
581
2,505 (avg. 4.3)
301 (51.8%)
10 (1.7%)
Transpose Transpose
492
2,312 (avg. 4.7)
262 (53.3%)
2 (0.4%)
Wordy Wordy
518
2,238 (avg. 4.3)
298 (57.5%)
6 (1.2%)
Anagram Anagram
3,062
9,653 (avg. 3.2)
2,199 (71.8%)
111 (3.6%)
Binary Search Tree Binary Search Tree
569
2,139 (avg. 3.8)
318 (55.9%)
7 (1.2%)
Clock Clock
477
1,898 (avg. 4.0)
320 (67.1%)
2 (0.4%)
Crypto Square Crypto Square
398
1,592 (avg. 4.0)
270 (67.8%)
2 (0.5%)
Dominoes Dominoes
1,016
2,878 (avg. 2.8)
249 (24.5%)
9 (0.9%)
Go Counting Go Counting
447
1,149 (avg. 2.6)
153 (34.2%)
0 (0.0%)
Markdown Markdown
840
1,738 (avg. 2.1)
336 (40.0%)
14 (1.7%)
Meetup Meetup
842
2,212 (avg. 2.6)
662 (78.6%)
12 (1.4%)
Poker Poker
682
2,157 (avg. 3.2)
198 (29.0%)
4 (0.6%)
SGF Parsing SGF Parsing
103
1,211 (avg. 11.8)
56 (54.4%)
2 (1.9%)
Simple Linked List Simple Linked List
657
3,224 (avg. 4.9)
403 (61.3%)
8 (1.2%)
Sublist Sublist
418
1,405 (avg. 3.4)
271 (64.8%)
0 (0.0%)
Tree Building Tree Building
275
580 (avg. 2.1)
121 (44.0%)
2 (0.7%)
Two Bucket Two Bucket
332
920 (avg. 2.8)
142 (42.8%)
3 (0.9%)
Word Search Word Search
812
2,278 (avg. 2.8)
244 (30.0%)
5 (0.6%)
Zebra Puzzle Zebra Puzzle
2,018
1,754 (avg. 0.9)
357 (17.7%)
5 (0.2%)
Zipper Zipper
252
712 (avg. 2.8)
109 (43.3%)
0 (0.0%)
Book Store Book Store
479
1,318 (avg. 2.8)
168 (35.1%)
5 (1.0%)
Change Change
455
2,208 (avg. 4.9)
183 (40.2%)
4 (0.9%)
Circular Buffer Circular Buffer
507
1,749 (avg. 3.4)
306 (60.4%)
4 (0.8%)
Complex Numbers Complex Numbers
505
1,630 (avg. 3.2)
313 (62.0%)
11 (2.2%)
Connect Connect
294
1,516 (avg. 5.2)
149 (50.7%)
7 (2.4%)
Hangman Hangman
277
676 (avg. 2.4)
66 (23.8%)
5 (1.8%)
List Ops List Ops
442
1,898 (avg. 4.3)
239 (54.1%)
8 (1.8%)
Mazy Mice Mazy Mice
83
505 (avg. 6.1)
36 (43.4%)
0 (0.0%)
OCR Numbers OCR Numbers
338
655 (avg. 1.9)
175 (51.8%)
3 (0.9%)
Palindrome Products Palindrome Products
402
1,143 (avg. 2.8)
209 (52.0%)
3 (0.7%)
POV POV
97
621 (avg. 6.4)
50 (51.5%)
1 (1.0%)
Rational Numbers Rational Numbers
396
2,232 (avg. 5.6)
217 (54.8%)
4 (1.0%)
React React
150
754 (avg. 5.0)
50 (33.3%)
1 (0.7%)
Rectangles Rectangles
307
794 (avg. 2.6)
152 (49.5%)
3 (1.0%)
Simple Cipher Simple Cipher
464
1,429 (avg. 3.1)
297 (64.0%)
7 (1.5%)
Forth Forth
461
1,507 (avg. 3.3)
183 (39.7%)
11 (2.4%)
Pythagorean Triplet Pythagorean Triplet
975
6,080 (avg. 6.2)
422 (43.3%)
6 (0.6%)
Custom Set Custom Set
457
1,560 (avg. 3.4)
212 (46.4%)
2 (0.4%)
Satellite Satellite
341
800 (avg. 2.3)
129 (37.8%)
2 (0.6%)
8 deprecated practice exercises
Started
Attempts
Completions
Mentoring requests
Accumulate Accumulate
110
138 (avg. 1.3)
107 (97.3%)
5 (4.5%)
Beer Song Beer Song
867
3,377 (avg. 3.9)
664 (76.6%)
15 (1.7%)
Binary Binary
136
180 (avg. 1.3)
133 (97.8%)
6 (4.4%)
Diffie-Hellman Diffie-Hellman
228
327 (avg. 1.4)
117 (51.3%)
2 (0.9%)
Hexadecimal Hexadecimal
58
73 (avg. 1.3)
55 (94.8%)
7 (12.1%)
Octal Octal
59
69 (avg. 1.2)
56 (94.9%)
2 (3.4%)
Strain Strain
111
141 (avg. 1.3)
107 (96.4%)
5 (4.5%)
Trinary Trinary
71
83 (avg. 1.2)
68 (95.8%)
1 (1.4%)
6 unimplemented practice exercises
Baffling Birthdays Baffling Birthdays
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Intergalactic Transmission Intergalactic Transmission
View dataThe link opens in a new window or tab
PaaS I/O PaaS I/O
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Relative Distance Relative Distance
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Split-Second Stopwatch Split-Second Stopwatch
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Swift Scheduling Swift Scheduling
View dataThe link opens in a new window or tab
1 foregone practice exercise
Lens Person Lens Person
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Programming Tags

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Help manage the tags used to group, filter and recommend solutions, approaches and articles.

0 tags

Test Runner

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

Current version: ed2225c79d632d3b04601f9c3ed8154c3c5cdfdb (Takes up to 10 mins to deploy)

Total Test Runner Runs
3,281,240
Test Run Pass Rate
17.3% (569069)
Test Run Fail Rate
37.8% (1239988)
Test Run Error Rate
44.9% (1472183)

Representer

Learn More

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

Current version: 4c426e72f23bc01160b2b06807c4c154c79c4dee (Takes up to 10 mins to deploy)

Total Representer Runs
712,524
Total Representation Comments Made
42,779
Feedback Given Frequency
6.0%

Analyzer

Learn More

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

Current version: a33dda12ff9a6f63f94a9e103fee9f6ba39946d4 (Takes up to 10 mins to deploy)

Total Analyzer Runs
428,150
Total Analysis Comments Made
244,474
Feedback Given Frequency
3.4%