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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
220,911
Submissions
3,573,552
Mentoring Discussions
16,563

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
45,648 learnt
Bo
Booleans
25,908 learnt
Ar
Arrays
12,233 learnt
Fo
For Loops
12,233 learnt
Fo
For-Each Loops
12,233 learnt
Ge
Generic Types
8,662 learnt
Li
Lists
8,662 learnt
Ex
Exceptions
3,793 learnt
Ch
Chars
8,433 learnt
Cl
Classes
8,150 learnt
Co
Constructors
5,994 learnt
In
Interfaces
4,476 learnt
If
If-Else Statements
12,960 learnt
Nu
Numbers
12,960 learnt
St
Strings
17,614 learnt
Te
Ternary Operators
7,223 learnt
Sw
Switch Statements
5,265 learnt
In
Inheritance
4,770 learnt
En
Enums
2,467 learnt
Nu
Nullability
4,054 learnt
Ra
Randomness
2,725 learnt
Da
Date-Time
2,769 learnt
Me
Method Overloading
2,048 learnt
Bi
Bit Manipulation
2,460 learnt
Se
Sets
1,822 learnt
Ma
Maps
680 learnt
22 active learning exercises
Started
Attempts
Completions
Mentoring requests
Cook Your Lasagna Cook Your Lasagna
74,576
410,449 (avg. 5.5)
45,648 (61.2%)
476 (0.6%)
Annalyn's Infiltration Annalyn's Infiltration
34,746
329,951 (avg. 9.5)
25,908 (74.6%)
303 (0.9%)
Bird Watcher Bird Watcher
14,686
202,224 (avg. 13.8)
12,233 (83.3%)
277 (1.9%)
Karl's Languages Karl's Languages
9,526
52,649 (avg. 5.5)
8,662 (90.9%)
72 (0.8%)
Calculator Conundrum Calculator Conundrum
4,612
64,204 (avg. 13.9)
3,793 (82.2%)
70 (1.5%)
Squeaky Clean Squeaky Clean
13,296
201,981 (avg. 15.2)
8,433 (63.4%)
399 (3.0%)
Jedlik's Toy Car Jedlik's Toy Car
8,906
75,929 (avg. 8.5)
8,150 (91.5%)
95 (1.1%)
Need for Speed Need for Speed
6,830
82,160 (avg. 12.0)
5,994 (87.8%)
63 (0.9%)
Remote Control Competition Remote Control Competition
5,643
61,509 (avg. 10.9)
4,476 (79.3%)
80 (1.4%)
Cars, Assemble! Cars, Assemble!
14,455
110,643 (avg. 7.7)
12,960 (89.7%)
269 (1.9%)
Log Levels Log Levels
27,426
248,021 (avg. 9.0)
17,614 (64.2%)
288 (1.1%)
Salary Calculator Salary Calculator
7,756
45,375 (avg. 5.9)
7,223 (93.1%)
38 (0.5%)
Football Match Reports Football Match Reports
5,428
23,188 (avg. 4.3)
5,265 (97.0%)
38 (0.7%)
Wizards and Warriors Wizards and Warriors
5,246
36,778 (avg. 7.0)
4,770 (90.9%)
35 (0.7%)
Logs, Logs, Logs! Logs, Logs, Logs!
2,879
29,590 (avg. 10.3)
2,467 (85.7%)
36 (1.3%)
Tim from Marketing Tim from Marketing
4,306
28,950 (avg. 6.7)
4,054 (94.1%)
54 (1.3%)
Captain's Log Captain's Log
2,911
18,955 (avg. 6.5)
2,725 (93.6%)
14 (0.5%)
Booking Up For Beauty Booking Up For Beauty
3,358
47,632 (avg. 14.2)
2,769 (82.5%)
31 (0.9%)
Wizards and Warriors 2 Wizards and Warriors 2
2,261
19,321 (avg. 8.5)
2,048 (90.6%)
18 (0.8%)
Secrets Secrets
2,835
16,197 (avg. 5.7)
2,460 (86.8%)
4 (0.1%)
Gotta Snatch 'Em All Gotta Snatch 'Em All
2,152
27,251 (avg. 12.7)
1,822 (84.7%)
30 (1.4%)
International Calling Connoisseur International Calling Connoisseur
777
8,719 (avg. 11.2)
680 (87.5%)
7 (0.9%)
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: d460a46669483215a000d5810ee24046279ea58f (Updates should be instant)

Next goal: Implement 135 practice exercises. Find out more.
129 active practice exercises
Started
Attempts
Completions
Mentoring requests
Hello World Hello World
164,065
341,322 (avg. 2.1)
104,511 (63.7%)
40 (0.0%)
Leap Leap
6,188
21,257 (avg. 3.4)
5,043 (81.5%)
93 (1.5%)
Reverse String Reverse String
14,374
42,351 (avg. 2.9)
12,007 (83.5%)
317 (2.2%)
Two Fer Two Fer
22,611
71,877 (avg. 3.2)
17,880 (79.1%)
3,919 (17.3%)
Armstrong Numbers Armstrong Numbers
6,043
18,845 (avg. 3.1)
4,751 (78.6%)
129 (2.1%)
Darts Darts
6,143
21,070 (avg. 3.4)
4,804 (78.2%)
60 (1.0%)
D&D Character D&D Character
4,063
31,450 (avg. 7.7)
2,832 (69.7%)
61 (1.5%)
DOT DSL DOT DSL
759
3,401 (avg. 4.5)
457 (60.2%)
5 (0.7%)
Grains Grains
3,986
30,478 (avg. 7.6)
3,219 (80.8%)
47 (1.2%)
High Scores High Scores
1,836
15,395 (avg. 8.4)
1,493 (81.3%)
31 (1.7%)
Resistor Color Resistor Color
5,910
20,843 (avg. 3.5)
4,708 (79.7%)
69 (1.2%)
Resistor Color Duo Resistor Color Duo
4,072
12,743 (avg. 3.1)
3,410 (83.7%)
41 (1.0%)
Resistor Color Trio Resistor Color Trio
1,108
13,274 (avg. 12.0)
936 (84.5%)
30 (2.7%)
RNA Transcription RNA Transcription
6,146
15,245 (avg. 2.5)
5,165 (84.0%)
234 (3.8%)
Acronym Acronym
4,072
15,946 (avg. 3.9)
3,227 (79.2%)
90 (2.2%)
Difference of Squares Difference of Squares
6,400
21,604 (avg. 3.4)
5,587 (87.3%)
706 (11.0%)
Gigasecond Gigasecond
8,155
19,102 (avg. 2.3)
5,810 (71.2%)
1,344 (16.5%)
Hamming Hamming
8,085
29,517 (avg. 3.7)
6,650 (82.3%)
1,490 (18.4%)
Micro Blog Micro Blog
6,103
34,990 (avg. 5.7)
3,689 (60.4%)
87 (1.4%)
Pangram Pangram
5,046
12,486 (avg. 2.5)
4,192 (83.1%)
169 (3.3%)
Perfect Numbers Perfect Numbers
3,218
11,837 (avg. 3.7)
2,194 (68.2%)
45 (1.4%)
Eliud's Eggs Eliud's Eggs
853
2,833 (avg. 3.3)
763 (89.4%)
9 (1.1%)
Protein Translation Protein Translation
3,299
14,882 (avg. 4.5)
2,597 (78.7%)
48 (1.5%)
Raindrops Raindrops
7,807
20,239 (avg. 2.6)
6,562 (84.1%)
252 (3.2%)
Say Say
2,276
14,083 (avg. 6.2)
932 (40.9%)
37 (1.6%)
Scrabble Score Scrabble Score
5,913
21,451 (avg. 3.6)
4,990 (84.4%)
1,080 (18.3%)
Secret Handshake Secret Handshake
3,925
19,142 (avg. 4.9)
2,994 (76.3%)
464 (11.8%)
Space Age Space Age
4,108
8,838 (avg. 2.2)
3,151 (76.7%)
60 (1.5%)
Collatz Conjecture Collatz Conjecture
1,671
6,313 (avg. 3.8)
1,391 (83.2%)
28 (1.7%)
Diamond Diamond
2,442
12,097 (avg. 5.0)
1,612 (66.0%)
49 (2.0%)
Error Handling Error Handling
1,579
11,488 (avg. 7.3)
891 (56.4%)
5 (0.3%)
ISBN Verifier ISBN Verifier
2,446
10,769 (avg. 4.4)
1,907 (78.0%)
40 (1.6%)
Isogram Isogram
4,792
17,838 (avg. 3.7)
3,860 (80.6%)
167 (3.5%)
Killer Sudoku Helper Killer Sudoku Helper
524
3,006 (avg. 5.7)
297 (56.7%)
13 (2.5%)
Kindergarten Garden Kindergarten Garden
1,098
3,196 (avg. 2.9)
804 (73.2%)
9 (0.8%)
Largest Series Product Largest Series Product
1,745
9,717 (avg. 5.6)
1,383 (79.3%)
19 (1.1%)
Luhn Luhn
2,396
11,252 (avg. 4.7)
1,863 (77.8%)
48 (2.0%)
Matrix Matrix
3,076
15,659 (avg. 5.1)
2,324 (75.6%)
312 (10.1%)
Nth Prime Nth Prime
1,322
4,621 (avg. 3.5)
1,014 (76.7%)
17 (1.3%)
Proverb Proverb
2,697
7,751 (avg. 2.9)
2,177 (80.7%)
32 (1.2%)
Rotational Cipher Rotational Cipher
2,324
11,571 (avg. 5.0)
1,957 (84.2%)
224 (9.6%)
Saddle Points Saddle Points
1,718
7,462 (avg. 4.3)
1,172 (68.2%)
160 (9.3%)
Sieve Sieve
1,351
3,665 (avg. 2.7)
1,078 (79.8%)
23 (1.7%)
Sum of Multiples Sum of Multiples
1,948
6,709 (avg. 3.4)
1,417 (72.7%)
36 (1.8%)
Triangle Triangle
2,781
11,024 (avg. 4.0)
2,367 (85.1%)
258 (9.3%)
Twelve Days Twelve Days
2,600
13,974 (avg. 5.4)
1,955 (75.2%)
33 (1.3%)
Variable Length Quantity Variable Length Quantity
614
2,058 (avg. 3.4)
316 (51.5%)
1 (0.2%)
Yacht Yacht
1,516
6,764 (avg. 4.5)
1,001 (66.0%)
29 (1.9%)
Allergies Allergies
1,226
4,133 (avg. 3.4)
945 (77.1%)
25 (2.0%)
Atbash Cipher Atbash Cipher
746
3,867 (avg. 5.2)
590 (79.1%)
8 (1.1%)
Bob Bob
2,006
11,592 (avg. 5.8)
1,642 (81.9%)
58 (2.9%)
Flatten Array Flatten Array
1,644
7,371 (avg. 4.5)
1,240 (75.4%)
135 (8.2%)
Conway's Game of Life Conway's Game of Life
283
1,209 (avg. 4.3)
160 (56.5%)
0 (0.0%)
Grep Grep
623
2,723 (avg. 4.4)
337 (54.1%)
5 (0.8%)
Knapsack Knapsack
870
3,884 (avg. 4.5)
513 (59.0%)
9 (1.0%)
Ledger Ledger
308
2,072 (avg. 6.7)
167 (54.2%)
8 (2.6%)
Matching Brackets Matching Brackets
724
2,657 (avg. 3.7)
521 (72.0%)
8 (1.1%)
Nucleotide Count Nucleotide Count
2,067
5,919 (avg. 2.9)
1,850 (89.5%)
89 (4.3%)
Pascal's Triangle Pascal's Triangle
746
1,881 (avg. 2.5)
524 (70.2%)
4 (0.5%)
Phone Number Phone Number
1,433
7,597 (avg. 5.3)
1,107 (77.3%)
24 (1.7%)
Pig Latin Pig Latin
2,646
11,009 (avg. 4.2)
1,457 (55.1%)
76 (2.9%)
Prime Factors Prime Factors
829
2,491 (avg. 3.0)
628 (75.8%)
11 (1.3%)
Relative Distance Relative Distance
87
649 (avg. 7.5)
38 (43.7%)
0 (0.0%)
Robot Name Robot Name
1,731
9,736 (avg. 5.6)
1,439 (83.1%)
137 (7.9%)
Run-Length Encoding Run-Length Encoding
601
2,258 (avg. 3.8)
424 (70.5%)
9 (1.5%)
Series Series
953
2,657 (avg. 2.8)
783 (82.2%)
11 (1.2%)
Square Root Square Root
452
1,327 (avg. 2.9)
356 (78.8%)
7 (1.5%)
Word Count Word Count
2,775
15,991 (avg. 5.8)
2,126 (76.6%)
212 (7.6%)
State Of Tic Tac Toe State Of Tic Tac Toe
217
1,434 (avg. 6.6)
127 (58.5%)
5 (2.3%)
Affine Cipher Affine Cipher
325
2,264 (avg. 7.0)
209 (64.3%)
3 (0.9%)
All Your Base All Your Base
462
2,180 (avg. 4.7)
311 (67.3%)
2 (0.4%)
Alphametics Alphametics
514
2,126 (avg. 4.1)
200 (38.9%)
3 (0.6%)
Bank Account Bank Account
1,514
8,356 (avg. 5.5)
1,081 (71.4%)
89 (5.9%)
Binary Search Binary Search
1,251
6,922 (avg. 5.5)
951 (76.0%)
93 (7.4%)
Bottle Song Bottle Song
652
6,217 (avg. 9.5)
422 (64.7%)
18 (2.8%)
Bowling Bowling
879
6,549 (avg. 7.5)
389 (44.3%)
11 (1.3%)
ETL ETL
1,752
2,595 (avg. 1.5)
1,604 (91.6%)
128 (7.3%)
Food Chain Food Chain
839
3,141 (avg. 3.7)
567 (67.6%)
10 (1.2%)
Grade School Grade School
754
2,428 (avg. 3.2)
557 (73.9%)
21 (2.8%)
House House
911
3,388 (avg. 3.7)
665 (73.0%)
9 (1.0%)
Linked List Linked List
1,335
5,716 (avg. 4.3)
953 (71.4%)
75 (5.6%)
Minesweeper Minesweeper
795
2,848 (avg. 3.6)
516 (64.9%)
9 (1.1%)
Parallel Letter Frequency Parallel Letter Frequency
689
3,242 (avg. 4.7)
436 (63.3%)
13 (1.9%)
Piecing It Together Piecing It Together
6
35 (avg. 5.8)
1 (16.7%)
0 (0.0%)
Queen Attack Queen Attack
1,993
7,517 (avg. 3.8)
727 (36.5%)
33 (1.7%)
Rail Fence Cipher Rail Fence Cipher
330
1,334 (avg. 4.0)
197 (59.7%)
1 (0.3%)
REST API REST API
628
2,967 (avg. 4.7)
149 (23.7%)
4 (0.6%)
Robot Simulator Robot Simulator
755
2,450 (avg. 3.2)
476 (63.0%)
10 (1.3%)
Roman Numerals Roman Numerals
1,114
3,323 (avg. 3.0)
825 (74.1%)
15 (1.3%)
Spiral Matrix Spiral Matrix
546
1,310 (avg. 2.4)
335 (61.4%)
6 (1.1%)
Tournament Tournament
611
2,756 (avg. 4.5)
319 (52.2%)
10 (1.6%)
Transpose Transpose
502
2,408 (avg. 4.8)
270 (53.8%)
2 (0.4%)
Wordy Wordy
529
2,360 (avg. 4.5)
308 (58.2%)
6 (1.1%)
Anagram Anagram
3,078
9,819 (avg. 3.2)
2,213 (71.9%)
111 (3.6%)
Binary Search Tree Binary Search Tree
589
2,416 (avg. 4.1)
330 (56.0%)
7 (1.2%)
Clock Clock
490
1,980 (avg. 4.0)
331 (67.6%)
3 (0.6%)
Crypto Square Crypto Square
408
1,651 (avg. 4.0)
279 (68.4%)
2 (0.5%)
Dominoes Dominoes
1,030
3,064 (avg. 3.0)
257 (25.0%)
9 (0.9%)
Go Counting Go Counting
457
1,381 (avg. 3.0)
162 (35.4%)
0 (0.0%)
Markdown Markdown
857
1,830 (avg. 2.1)
346 (40.4%)
14 (1.6%)
Meetup Meetup
854
2,280 (avg. 2.7)
673 (78.8%)
12 (1.4%)
Poker Poker
693
2,380 (avg. 3.4)
206 (29.7%)
4 (0.6%)
SGF Parsing SGF Parsing
113
1,637 (avg. 14.5)
62 (54.9%)
2 (1.8%)
Simple Linked List Simple Linked List
676
3,590 (avg. 5.3)
415 (61.4%)
9 (1.3%)
Sublist Sublist
429
1,520 (avg. 3.5)
281 (65.5%)
0 (0.0%)
Tree Building Tree Building
287
686 (avg. 2.4)
127 (44.3%)
2 (0.7%)
Two Bucket Two Bucket
341
998 (avg. 2.9)
148 (43.4%)
3 (0.9%)
Word Search Word Search
822
2,430 (avg. 3.0)
249 (30.3%)
5 (0.6%)
Zebra Puzzle Zebra Puzzle
2,337
2,097 (avg. 0.9)
395 (16.9%)
7 (0.3%)
Zipper Zipper
263
814 (avg. 3.1)
116 (44.1%)
0 (0.0%)
Book Store Book Store
502
1,546 (avg. 3.1)
177 (35.3%)
5 (1.0%)
Change Change
472
2,472 (avg. 5.2)
195 (41.3%)
4 (0.8%)
Circular Buffer Circular Buffer
524
1,941 (avg. 3.7)
317 (60.5%)
4 (0.8%)
Complex Numbers Complex Numbers
534
1,719 (avg. 3.2)
333 (62.4%)
11 (2.1%)
Connect Connect
304
1,573 (avg. 5.2)
157 (51.6%)
7 (2.3%)
Hangman Hangman
290
719 (avg. 2.5)
71 (24.5%)
5 (1.7%)
List Ops List Ops
455
1,931 (avg. 4.2)
248 (54.5%)
8 (1.8%)
Mazy Mice Mazy Mice
95
566 (avg. 6.0)
44 (46.3%)
1 (1.1%)
OCR Numbers OCR Numbers
347
688 (avg. 2.0)
180 (51.9%)
3 (0.9%)
Palindrome Products Palindrome Products
412
1,177 (avg. 2.9)
216 (52.4%)
3 (0.7%)
POV POV
104
672 (avg. 6.5)
55 (52.9%)
1 (1.0%)
Rational Numbers Rational Numbers
413
2,384 (avg. 5.8)
226 (54.7%)
4 (1.0%)
React React
166
854 (avg. 5.1)
56 (33.7%)
1 (0.6%)
Rectangles Rectangles
314
809 (avg. 2.6)
159 (50.6%)
3 (1.0%)
Simple Cipher Simple Cipher
472
1,481 (avg. 3.1)
305 (64.6%)
7 (1.5%)
Forth Forth
469
1,548 (avg. 3.3)
188 (40.1%)
11 (2.3%)
Pythagorean Triplet Pythagorean Triplet
987
6,190 (avg. 6.3)
428 (43.4%)
6 (0.6%)
Custom Set Custom Set
476
1,603 (avg. 3.4)
220 (46.2%)
2 (0.4%)
Satellite Satellite
359
836 (avg. 2.3)
137 (38.2%)
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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Flower Field Flower Field
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Intergalactic Transmission Intergalactic Transmission
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PaaS I/O PaaS I/O
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Split-Second Stopwatch Split-Second Stopwatch
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Swift Scheduling Swift Scheduling
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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: 6f98e8a41f72cf36971d07653318e1601c233657 (Takes up to 10 mins to deploy)

Total Test Runner Runs
3,496,066
Test Run Pass Rate
17.3% (604483)
Test Run Fail Rate
37.9% (1325453)
Test Run Error Rate
44.8% (1566130)

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: 1726a82b7954ee558f8e9389ddea45ecb3656161 (Takes up to 10 mins to deploy)

Total Representer Runs
744,141
Total Representation Comments Made
49,752
Feedback Given Frequency
6.7%

Analyzer

Learn More

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

Current version: b394ec25148d5d3b82efcd62962ace5664182090 (Takes up to 10 mins to deploy)

Total Analyzer Runs
459,675
Total Analysis Comments Made
270,111
Feedback Given Frequency
3.5%