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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
213,982
Submissions
3,416,927
Mentoring Discussions
16,375

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
43,718 learnt
Bo
Booleans
24,772 learnt
Ar
Arrays
11,608 learnt
Fo
For Loops
11,608 learnt
Fo
For-Each Loops
11,608 learnt
Ge
Generic Types
8,217 learnt
Li
Lists
8,217 learnt
Ex
Exceptions
3,491 learnt
Ch
Chars
7,942 learnt
Cl
Classes
7,697 learnt
Co
Constructors
5,687 learnt
In
Interfaces
4,237 learnt
If
If-Else Statements
12,239 learnt
Nu
Numbers
12,239 learnt
St
Strings
16,818 learnt
Te
Ternary Operators
6,806 learnt
Sw
Switch Statements
4,974 learnt
In
Inheritance
4,523 learnt
En
Enums
2,281 learnt
Nu
Nullability
3,681 learnt
Ra
Randomness
2,486 learnt
Da
Date-Time
2,525 learnt
Me
Method Overloading
1,885 learnt
Bi
Bit Manipulation
2,218 learnt
Se
Sets
1,639 learnt
Ma
Maps
450 learnt
22 active learning exercises
Started
Attempts
Completions
Mentoring requests
Cook Your Lasagna Cook Your Lasagna
71,373
392,990 (avg. 5.5)
43,718 (61.3%)
470 (0.7%)
Annalyn's Infiltration Annalyn's Infiltration
33,190
315,132 (avg. 9.5)
24,772 (74.6%)
303 (0.9%)
Bird Watcher Bird Watcher
13,920
191,815 (avg. 13.8)
11,608 (83.4%)
260 (1.9%)
Karl's Languages Karl's Languages
8,999
49,493 (avg. 5.5)
8,217 (91.3%)
68 (0.8%)
Calculator Conundrum Calculator Conundrum
4,248
59,103 (avg. 13.9)
3,491 (82.2%)
66 (1.6%)
Squeaky Clean Squeaky Clean
12,621
193,296 (avg. 15.3)
7,942 (62.9%)
377 (3.0%)
Jedlik's Toy Car Jedlik's Toy Car
8,399
70,894 (avg. 8.4)
7,697 (91.6%)
90 (1.1%)
Need for Speed Need for Speed
6,460
77,476 (avg. 12.0)
5,687 (88.0%)
63 (1.0%)
Remote Control Competition Remote Control Competition
5,348
58,467 (avg. 10.9)
4,237 (79.2%)
78 (1.5%)
Cars, Assemble! Cars, Assemble!
13,649
104,479 (avg. 7.7)
12,239 (89.7%)
249 (1.8%)
Log Levels Log Levels
26,271
237,015 (avg. 9.0)
16,818 (64.0%)
283 (1.1%)
Salary Calculator Salary Calculator
7,312
42,639 (avg. 5.8)
6,806 (93.1%)
38 (0.5%)
Football Match Reports Football Match Reports
5,127
21,673 (avg. 4.2)
4,974 (97.0%)
36 (0.7%)
Wizards and Warriors Wizards and Warriors
4,971
34,642 (avg. 7.0)
4,523 (91.0%)
35 (0.7%)
Logs, Logs, Logs! Logs, Logs, Logs!
2,673
27,487 (avg. 10.3)
2,281 (85.3%)
35 (1.3%)
Tim from Marketing Tim from Marketing
3,909
26,460 (avg. 6.8)
3,681 (94.2%)
53 (1.4%)
Captain's Log Captain's Log
2,654
17,237 (avg. 6.5)
2,486 (93.7%)
13 (0.5%)
Booking Up For Beauty Booking Up For Beauty
3,068
43,780 (avg. 14.3)
2,525 (82.3%)
27 (0.9%)
Wizards and Warriors 2 Wizards and Warriors 2
2,080
17,700 (avg. 8.5)
1,885 (90.6%)
18 (0.9%)
Secrets Secrets
2,568
14,658 (avg. 5.7)
2,218 (86.4%)
4 (0.2%)
Gotta Snatch 'Em All Gotta Snatch 'Em All
1,948
24,877 (avg. 12.8)
1,639 (84.1%)
27 (1.4%)
International Calling Connoisseur International Calling Connoisseur
533
6,072 (avg. 11.4)
450 (84.4%)
4 (0.8%)
1 deprecated learning exercises
Started
Attempts
Completions
Mentoring requests
Play Your Cards! Play Your Cards!
8,676
85,882 (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: a6065865cd7bde56026407f1fe43c7373d6657ff (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
157,729
328,415 (avg. 2.1)
100,730 (63.9%)
40 (0.0%)
Leap Leap
5,914
20,013 (avg. 3.4)
4,813 (81.4%)
89 (1.5%)
Reverse String Reverse String
14,167
41,706 (avg. 2.9)
11,822 (83.4%)
317 (2.2%)
Two Fer Two Fer
22,421
71,066 (avg. 3.2)
17,706 (79.0%)
3,919 (17.5%)
Armstrong Numbers Armstrong Numbers
5,838
17,874 (avg. 3.1)
4,569 (78.3%)
128 (2.2%)
Darts Darts
5,958
20,303 (avg. 3.4)
4,638 (77.8%)
59 (1.0%)
D&D Character D&D Character
3,939
30,011 (avg. 7.6)
2,747 (69.7%)
61 (1.5%)
DOT DSL DOT DSL
651
2,990 (avg. 4.6)
396 (60.8%)
4 (0.6%)
Grains Grains
3,855
29,284 (avg. 7.6)
3,104 (80.5%)
47 (1.2%)
High Scores High Scores
1,728
14,763 (avg. 8.5)
1,407 (81.4%)
31 (1.8%)
Resistor Color Resistor Color
5,807
20,389 (avg. 3.5)
4,615 (79.5%)
67 (1.2%)
Resistor Color Duo Resistor Color Duo
3,986
12,425 (avg. 3.1)
3,337 (83.7%)
40 (1.0%)
Resistor Color Trio Resistor Color Trio
1,025
12,373 (avg. 12.1)
866 (84.5%)
29 (2.8%)
RNA Transcription RNA Transcription
6,062
14,924 (avg. 2.5)
5,092 (84.0%)
232 (3.8%)
Acronym Acronym
3,983
15,268 (avg. 3.8)
3,152 (79.1%)
90 (2.3%)
Difference of Squares Difference of Squares
6,295
21,205 (avg. 3.4)
5,488 (87.2%)
705 (11.2%)
Gigasecond Gigasecond
8,098
18,917 (avg. 2.3)
5,758 (71.1%)
1,343 (16.6%)
Hamming Hamming
8,009
29,155 (avg. 3.6)
6,583 (82.2%)
1,489 (18.6%)
Micro Blog Micro Blog
6,007
34,553 (avg. 5.8)
3,630 (60.4%)
84 (1.4%)
Pangram Pangram
4,969
12,136 (avg. 2.4)
4,122 (83.0%)
168 (3.4%)
Perfect Numbers Perfect Numbers
3,169
11,592 (avg. 3.7)
2,149 (67.8%)
42 (1.3%)
Eliud's Eggs Eliud's Eggs
794
2,666 (avg. 3.4)
710 (89.4%)
7 (0.9%)
Protein Translation Protein Translation
3,236
14,248 (avg. 4.4)
2,543 (78.6%)
47 (1.5%)
Raindrops Raindrops
7,729
19,938 (avg. 2.6)
6,490 (84.0%)
250 (3.2%)
Say Say
2,214
13,599 (avg. 6.1)
897 (40.5%)
35 (1.6%)
Scrabble Score Scrabble Score
5,861
21,280 (avg. 3.6)
4,950 (84.5%)
1,080 (18.4%)
Secret Handshake Secret Handshake
3,886
18,628 (avg. 4.8)
2,957 (76.1%)
464 (11.9%)
Space Age Space Age
4,023
8,526 (avg. 2.1)
3,092 (76.9%)
60 (1.5%)
Collatz Conjecture Collatz Conjecture
1,600
5,954 (avg. 3.7)
1,327 (82.9%)
27 (1.7%)
Diamond Diamond
2,372
11,508 (avg. 4.9)
1,567 (66.1%)
46 (1.9%)
Error Handling Error Handling
1,528
11,002 (avg. 7.2)
856 (56.0%)
5 (0.3%)
ISBN Verifier ISBN Verifier
2,392
10,397 (avg. 4.3)
1,862 (77.8%)
40 (1.7%)
Isogram Isogram
4,735
17,587 (avg. 3.7)
3,808 (80.4%)
166 (3.5%)
Killer Sudoku Helper Killer Sudoku Helper
486
2,748 (avg. 5.7)
275 (56.6%)
12 (2.5%)
Kindergarten Garden Kindergarten Garden
1,067
3,039 (avg. 2.8)
778 (72.9%)
9 (0.8%)
Largest Series Product Largest Series Product
1,710
9,243 (avg. 5.4)
1,355 (79.2%)
19 (1.1%)
Luhn Luhn
2,350
10,864 (avg. 4.6)
1,825 (77.7%)
48 (2.0%)
Matrix Matrix
3,041
15,339 (avg. 5.0)
2,295 (75.5%)
312 (10.3%)
Nth Prime Nth Prime
1,295
4,441 (avg. 3.4)
993 (76.7%)
15 (1.2%)
Proverb Proverb
2,659
7,572 (avg. 2.8)
2,149 (80.8%)
32 (1.2%)
Rotational Cipher Rotational Cipher
2,301
11,435 (avg. 5.0)
1,937 (84.2%)
224 (9.7%)
Saddle Points Saddle Points
1,696
7,331 (avg. 4.3)
1,153 (68.0%)
160 (9.4%)
Sieve Sieve
1,327
3,527 (avg. 2.7)
1,059 (79.8%)
23 (1.7%)
Sum of Multiples Sum of Multiples
1,914
6,541 (avg. 3.4)
1,387 (72.5%)
35 (1.8%)
Triangle Triangle
2,755
10,899 (avg. 4.0)
2,346 (85.2%)
258 (9.4%)
Twelve Days Twelve Days
2,575
13,806 (avg. 5.4)
1,938 (75.3%)
33 (1.3%)
Variable Length Quantity Variable Length Quantity
597
1,974 (avg. 3.3)
303 (50.8%)
1 (0.2%)
Yacht Yacht
1,500
6,662 (avg. 4.4)
988 (65.9%)
29 (1.9%)
Allergies Allergies
1,208
4,033 (avg. 3.3)
932 (77.2%)
25 (2.1%)
Atbash Cipher Atbash Cipher
729
3,734 (avg. 5.1)
576 (79.0%)
7 (1.0%)
Bob Bob
1,980
11,383 (avg. 5.7)
1,622 (81.9%)
58 (2.9%)
Flatten Array Flatten Array
1,628
7,278 (avg. 4.5)
1,225 (75.2%)
135 (8.3%)
Conway's Game of Life Conway's Game of Life
255
988 (avg. 3.9)
139 (54.5%)
0 (0.0%)
Grep Grep
613
2,566 (avg. 4.2)
327 (53.3%)
5 (0.8%)
Knapsack Knapsack
852
3,816 (avg. 4.5)
503 (59.0%)
9 (1.1%)
Ledger Ledger
293
1,946 (avg. 6.6)
157 (53.6%)
7 (2.4%)
Matching Brackets Matching Brackets
706
2,538 (avg. 3.6)
507 (71.8%)
8 (1.1%)
Nucleotide Count Nucleotide Count
2,049
5,834 (avg. 2.8)
1,834 (89.5%)
89 (4.3%)
Pascal's Triangle Pascal's Triangle
729
1,819 (avg. 2.5)
509 (69.8%)
4 (0.5%)
Phone Number Phone Number
1,413
7,359 (avg. 5.2)
1,094 (77.4%)
24 (1.7%)
Pig Latin Pig Latin
2,635
10,904 (avg. 4.1)
1,449 (55.0%)
76 (2.9%)
Prime Factors Prime Factors
816
2,460 (avg. 3.0)
616 (75.5%)
11 (1.3%)
Robot Name Robot Name
1,715
9,648 (avg. 5.6)
1,427 (83.2%)
137 (8.0%)
Run-Length Encoding Run-Length Encoding
592
2,209 (avg. 3.7)
416 (70.3%)
9 (1.5%)
Series Series
937
2,579 (avg. 2.8)
770 (82.2%)
11 (1.2%)
Square Root Square Root
426
1,253 (avg. 2.9)
337 (79.1%)
7 (1.6%)
Word Count Word Count
2,760
15,908 (avg. 5.8)
2,114 (76.6%)
212 (7.7%)
State Of Tic Tac Toe State Of Tic Tac Toe
201
1,337 (avg. 6.7)
119 (59.2%)
5 (2.5%)
Affine Cipher Affine Cipher
318
2,207 (avg. 6.9)
203 (63.8%)
3 (0.9%)
All Your Base All Your Base
453
2,135 (avg. 4.7)
303 (66.9%)
2 (0.4%)
Alphametics Alphametics
504
2,063 (avg. 4.1)
194 (38.5%)
3 (0.6%)
Bank Account Bank Account
1,498
8,277 (avg. 5.5)
1,072 (71.6%)
89 (5.9%)
Binary Search Binary Search
1,239
6,891 (avg. 5.6)
940 (75.9%)
93 (7.5%)
Bottle Song Bottle Song
631
6,118 (avg. 9.7)
407 (64.5%)
18 (2.9%)
Bowling Bowling
865
6,486 (avg. 7.5)
384 (44.4%)
11 (1.3%)
ETL ETL
1,740
2,543 (avg. 1.5)
1,595 (91.7%)
128 (7.4%)
Food Chain Food Chain
823
3,062 (avg. 3.7)
556 (67.6%)
10 (1.2%)
Grade School Grade School
744
2,361 (avg. 3.2)
547 (73.5%)
21 (2.8%)
House House
894
3,288 (avg. 3.7)
655 (73.3%)
9 (1.0%)
Linked List Linked List
1,318
5,557 (avg. 4.2)
942 (71.5%)
75 (5.7%)
Minesweeper Minesweeper
782
2,816 (avg. 3.6)
508 (65.0%)
9 (1.2%)
Parallel Letter Frequency Parallel Letter Frequency
675
3,143 (avg. 4.7)
423 (62.7%)
12 (1.8%)
Queen Attack Queen Attack
1,982
7,479 (avg. 3.8)
719 (36.3%)
33 (1.7%)
Rail Fence Cipher Rail Fence Cipher
322
1,261 (avg. 3.9)
189 (58.7%)
1 (0.3%)
REST API REST API
604
2,614 (avg. 4.3)
140 (23.2%)
4 (0.7%)
Robot Simulator Robot Simulator
737
2,306 (avg. 3.1)
465 (63.1%)
10 (1.4%)
Roman Numerals Roman Numerals
1,099
3,279 (avg. 3.0)
815 (74.2%)
15 (1.4%)
Spiral Matrix Spiral Matrix
532
1,263 (avg. 2.4)
325 (61.1%)
6 (1.1%)
Tournament Tournament
587
2,612 (avg. 4.4)
306 (52.1%)
10 (1.7%)
Transpose Transpose
493
2,332 (avg. 4.7)
263 (53.3%)
2 (0.4%)
Wordy Wordy
519
2,267 (avg. 4.4)
299 (57.6%)
6 (1.2%)
Anagram Anagram
3,065
9,678 (avg. 3.2)
2,201 (71.8%)
111 (3.6%)
Binary Search Tree Binary Search Tree
571
2,164 (avg. 3.8)
319 (55.9%)
7 (1.2%)
Clock Clock
479
1,914 (avg. 4.0)
321 (67.0%)
2 (0.4%)
Crypto Square Crypto Square
400
1,629 (avg. 4.1)
271 (67.8%)
2 (0.5%)
Dominoes Dominoes
1,019
2,898 (avg. 2.8)
250 (24.5%)
9 (0.9%)
Go Counting Go Counting
449
1,193 (avg. 2.7)
156 (34.7%)
0 (0.0%)
Markdown Markdown
842
1,763 (avg. 2.1)
338 (40.1%)
14 (1.7%)
Meetup Meetup
844
2,229 (avg. 2.6)
664 (78.7%)
12 (1.4%)
Poker Poker
684
2,162 (avg. 3.2)
198 (28.9%)
4 (0.6%)
SGF Parsing SGF Parsing
103
1,222 (avg. 11.9)
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
419
1,406 (avg. 3.4)
272 (64.9%)
0 (0.0%)
Tree Building Tree Building
275
580 (avg. 2.1)
121 (44.0%)
2 (0.7%)
Two Bucket Two Bucket
332
932 (avg. 2.8)
142 (42.8%)
3 (0.9%)
Word Search Word Search
812
2,280 (avg. 2.8)
244 (30.0%)
5 (0.6%)
Zebra Puzzle Zebra Puzzle
2,105
1,805 (avg. 0.9)
363 (17.2%)
6 (0.3%)
Zipper Zipper
253
712 (avg. 2.8)
109 (43.1%)
0 (0.0%)
Book Store Book Store
485
1,368 (avg. 2.8)
168 (34.6%)
5 (1.0%)
Change Change
458
2,272 (avg. 5.0)
184 (40.2%)
4 (0.9%)
Circular Buffer Circular Buffer
511
1,781 (avg. 3.5)
308 (60.3%)
4 (0.8%)
Complex Numbers Complex Numbers
513
1,662 (avg. 3.2)
318 (62.0%)
11 (2.1%)
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
512 (avg. 6.2)
36 (43.4%)
0 (0.0%)
OCR Numbers OCR Numbers
339
655 (avg. 1.9)
175 (51.6%)
3 (0.9%)
Palindrome Products Palindrome Products
402
1,143 (avg. 2.8)
209 (52.0%)
3 (0.7%)
POV POV
98
621 (avg. 6.3)
50 (51.0%)
1 (1.0%)
Rational Numbers Rational Numbers
400
2,284 (avg. 5.7)
220 (55.0%)
4 (1.0%)
React React
155
768 (avg. 5.0)
50 (32.3%)
1 (0.6%)
Rectangles Rectangles
307
794 (avg. 2.6)
152 (49.5%)
3 (1.0%)
Simple Cipher Simple Cipher
466
1,469 (avg. 3.2)
299 (64.2%)
7 (1.5%)
Forth Forth
462
1,507 (avg. 3.3)
183 (39.6%)
11 (2.4%)
Pythagorean Triplet Pythagorean Triplet
977
6,125 (avg. 6.3)
422 (43.2%)
6 (0.6%)
Custom Set Custom Set
462
1,560 (avg. 3.4)
212 (45.9%)
2 (0.4%)
Satellite Satellite
346
802 (avg. 2.3)
131 (37.9%)
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
View dataThe link opens in a new window or tab
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

Learn More

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

Current version: 92ed661f9adbcf71ba043064e39147518fff7018 (Takes up to 10 mins to deploy)

Total Test Runner Runs
3,340,888
Test Run Pass Rate
17.3% (578582)
Test Run Fail Rate
37.8% (1264108)
Test Run Error Rate
44.8% (1498198)

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: 05b600429985b161f3f65263163e1e080379bb71 (Takes up to 10 mins to deploy)

Total Representer Runs
721,125
Total Representation Comments Made
44,704
Feedback Given Frequency
6.2%

Analyzer

Learn More

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

Current version: 1fc0930b22bc89eb6c869eaa52ca23542ad80ee2 (Takes up to 10 mins to deploy)

Total Analyzer Runs
436,730
Total Analysis Comments Made
251,251
Feedback Given Frequency
3.4%