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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
217,327
Submissions
3,499,476
Mentoring Discussions
16,479

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
44,740 learnt
Bo
Booleans
25,382 learnt
Ar
Arrays
11,932 learnt
Fo
For Loops
11,932 learnt
Fo
For-Each Loops
11,932 learnt
Ge
Generic Types
8,461 learnt
Li
Lists
8,461 learnt
Ex
Exceptions
3,640 learnt
Ch
Chars
8,198 learnt
Cl
Classes
7,940 learnt
Co
Constructors
5,853 learnt
In
Interfaces
4,370 learnt
If
If-Else Statements
12,609 learnt
Nu
Numbers
12,609 learnt
St
Strings
17,252 learnt
Te
Ternary Operators
7,026 learnt
Sw
Switch Statements
5,137 learnt
In
Inheritance
4,656 learnt
En
Enums
2,390 learnt
Nu
Nullability
3,882 learnt
Ra
Randomness
2,622 learnt
Da
Date-Time
2,658 learnt
Me
Method Overloading
1,974 learnt
Bi
Bit Manipulation
2,359 learnt
Se
Sets
1,743 learnt
Ma
Maps
584 learnt
22 active learning exercises
Started
Attempts
Completions
Mentoring requests
Cook Your Lasagna Cook Your Lasagna
73,014
402,047 (avg. 5.5)
44,740 (61.3%)
474 (0.6%)
Annalyn's Infiltration Annalyn's Infiltration
34,026
322,825 (avg. 9.5)
25,382 (74.6%)
303 (0.9%)
Bird Watcher Bird Watcher
14,314
196,966 (avg. 13.8)
11,932 (83.4%)
269 (1.9%)
Karl's Languages Karl's Languages
9,296
51,138 (avg. 5.5)
8,461 (91.0%)
69 (0.7%)
Calculator Conundrum Calculator Conundrum
4,432
61,774 (avg. 13.9)
3,640 (82.1%)
67 (1.5%)
Squeaky Clean Squeaky Clean
12,986
197,670 (avg. 15.2)
8,198 (63.1%)
390 (3.0%)
Jedlik's Toy Car Jedlik's Toy Car
8,671
73,573 (avg. 8.5)
7,940 (91.6%)
93 (1.1%)
Need for Speed Need for Speed
6,671
80,148 (avg. 12.0)
5,853 (87.7%)
63 (0.9%)
Remote Control Competition Remote Control Competition
5,510
60,149 (avg. 10.9)
4,370 (79.3%)
78 (1.4%)
Cars, Assemble! Cars, Assemble!
14,069
107,275 (avg. 7.6)
12,609 (89.6%)
261 (1.9%)
Log Levels Log Levels
26,873
242,610 (avg. 9.0)
17,252 (64.2%)
285 (1.1%)
Salary Calculator Salary Calculator
7,543
43,996 (avg. 5.8)
7,026 (93.1%)
38 (0.5%)
Football Match Reports Football Match Reports
5,296
22,505 (avg. 4.2)
5,137 (97.0%)
37 (0.7%)
Wizards and Warriors Wizards and Warriors
5,126
35,793 (avg. 7.0)
4,656 (90.8%)
35 (0.7%)
Logs, Logs, Logs! Logs, Logs, Logs!
2,789
28,613 (avg. 10.3)
2,390 (85.7%)
35 (1.3%)
Tim from Marketing Tim from Marketing
4,125
27,738 (avg. 6.7)
3,882 (94.1%)
54 (1.3%)
Captain's Log Captain's Log
2,799
18,201 (avg. 6.5)
2,622 (93.7%)
13 (0.5%)
Booking Up For Beauty Booking Up For Beauty
3,220
45,978 (avg. 14.3)
2,658 (82.5%)
29 (0.9%)
Wizards and Warriors 2 Wizards and Warriors 2
2,180
18,519 (avg. 8.5)
1,974 (90.6%)
18 (0.8%)
Secrets Secrets
2,721
15,435 (avg. 5.7)
2,359 (86.7%)
4 (0.1%)
Gotta Snatch 'Em All Gotta Snatch 'Em All
2,064
26,067 (avg. 12.6)
1,743 (84.4%)
28 (1.4%)
International Calling Connoisseur International Calling Connoisseur
671
7,507 (avg. 11.2)
584 (87.0%)
5 (0.7%)
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: 276d466462fde3297661b47bc98a2eb42a90f092 (Updates should be instant)

Next goal: Implement 134 practice exercises. Find out more.
128 active practice exercises
Started
Attempts
Completions
Mentoring requests
Hello World Hello World
160,839
334,845 (avg. 2.1)
102,638 (63.8%)
40 (0.0%)
Leap Leap
6,066
20,622 (avg. 3.4)
4,939 (81.4%)
91 (1.5%)
Reverse String Reverse String
14,289
42,065 (avg. 2.9)
11,936 (83.5%)
317 (2.2%)
Two Fer Two Fer
22,535
71,503 (avg. 3.2)
17,810 (79.0%)
3,919 (17.4%)
Armstrong Numbers Armstrong Numbers
5,961
18,383 (avg. 3.1)
4,675 (78.4%)
129 (2.2%)
Darts Darts
6,059
20,696 (avg. 3.4)
4,729 (78.0%)
60 (1.0%)
D&D Character D&D Character
4,009
30,858 (avg. 7.7)
2,793 (69.7%)
61 (1.5%)
DOT DSL DOT DSL
709
3,206 (avg. 4.5)
433 (61.1%)
5 (0.7%)
Grains Grains
3,921
29,852 (avg. 7.6)
3,163 (80.7%)
47 (1.2%)
High Scores High Scores
1,793
15,073 (avg. 8.4)
1,457 (81.3%)
31 (1.7%)
Resistor Color Resistor Color
5,865
20,621 (avg. 3.5)
4,667 (79.6%)
69 (1.2%)
Resistor Color Duo Resistor Color Duo
4,037
12,603 (avg. 3.1)
3,381 (83.8%)
41 (1.0%)
Resistor Color Trio Resistor Color Trio
1,075
12,778 (avg. 11.9)
906 (84.3%)
29 (2.7%)
RNA Transcription RNA Transcription
6,112
15,108 (avg. 2.5)
5,139 (84.1%)
233 (3.8%)
Acronym Acronym
4,043
15,637 (avg. 3.9)
3,201 (79.2%)
90 (2.2%)
Difference of Squares Difference of Squares
6,358
21,416 (avg. 3.4)
5,550 (87.3%)
706 (11.1%)
Gigasecond Gigasecond
8,135
19,051 (avg. 2.3)
5,792 (71.2%)
1,344 (16.5%)
Hamming Hamming
8,057
29,339 (avg. 3.6)
6,624 (82.2%)
1,490 (18.5%)
Micro Blog Micro Blog
6,062
34,774 (avg. 5.7)
3,667 (60.5%)
86 (1.4%)
Pangram Pangram
5,014
12,320 (avg. 2.5)
4,163 (83.0%)
169 (3.4%)
Perfect Numbers Perfect Numbers
3,200
11,754 (avg. 3.7)
2,176 (68.0%)
44 (1.4%)
Eliud's Eggs Eliud's Eggs
831
2,776 (avg. 3.3)
742 (89.3%)
9 (1.1%)
Protein Translation Protein Translation
3,270
14,629 (avg. 4.5)
2,573 (78.7%)
47 (1.4%)
Raindrops Raindrops
7,769
20,101 (avg. 2.6)
6,530 (84.1%)
251 (3.2%)
Say Say
2,251
13,888 (avg. 6.2)
918 (40.8%)
35 (1.6%)
Scrabble Score Scrabble Score
5,888
21,365 (avg. 3.6)
4,973 (84.5%)
1,080 (18.3%)
Secret Handshake Secret Handshake
3,906
19,009 (avg. 4.9)
2,979 (76.3%)
464 (11.9%)
Space Age Space Age
4,074
8,712 (avg. 2.1)
3,125 (76.7%)
60 (1.5%)
Collatz Conjecture Collatz Conjecture
1,649
6,206 (avg. 3.8)
1,371 (83.1%)
28 (1.7%)
Diamond Diamond
2,411
11,830 (avg. 4.9)
1,597 (66.2%)
49 (2.0%)
Error Handling Error Handling
1,562
11,372 (avg. 7.3)
879 (56.3%)
5 (0.3%)
ISBN Verifier ISBN Verifier
2,422
10,610 (avg. 4.4)
1,888 (78.0%)
40 (1.7%)
Isogram Isogram
4,772
17,735 (avg. 3.7)
3,841 (80.5%)
166 (3.5%)
Killer Sudoku Helper Killer Sudoku Helper
511
2,915 (avg. 5.7)
292 (57.1%)
13 (2.5%)
Kindergarten Garden Kindergarten Garden
1,087
3,156 (avg. 2.9)
794 (73.0%)
9 (0.8%)
Largest Series Product Largest Series Product
1,732
9,615 (avg. 5.6)
1,373 (79.3%)
19 (1.1%)
Luhn Luhn
2,376
11,070 (avg. 4.7)
1,846 (77.7%)
48 (2.0%)
Matrix Matrix
3,061
15,564 (avg. 5.1)
2,311 (75.5%)
312 (10.2%)
Nth Prime Nth Prime
1,311
4,575 (avg. 3.5)
1,008 (76.9%)
16 (1.2%)
Proverb Proverb
2,678
7,635 (avg. 2.9)
2,163 (80.8%)
32 (1.2%)
Rotational Cipher Rotational Cipher
2,313
11,523 (avg. 5.0)
1,948 (84.2%)
224 (9.7%)
Saddle Points Saddle Points
1,707
7,409 (avg. 4.3)
1,163 (68.1%)
160 (9.4%)
Sieve Sieve
1,342
3,650 (avg. 2.7)
1,072 (79.9%)
23 (1.7%)
Sum of Multiples Sum of Multiples
1,938
6,674 (avg. 3.4)
1,409 (72.7%)
35 (1.8%)
Triangle Triangle
2,773
10,983 (avg. 4.0)
2,360 (85.1%)
258 (9.3%)
Twelve Days Twelve Days
2,591
13,928 (avg. 5.4)
1,949 (75.2%)
33 (1.3%)
Variable Length Quantity Variable Length Quantity
610
2,038 (avg. 3.3)
313 (51.3%)
1 (0.2%)
Yacht Yacht
1,511
6,723 (avg. 4.4)
998 (66.0%)
29 (1.9%)
Allergies Allergies
1,222
4,113 (avg. 3.4)
941 (77.0%)
25 (2.0%)
Atbash Cipher Atbash Cipher
739
3,831 (avg. 5.2)
586 (79.3%)
7 (0.9%)
Bob Bob
1,997
11,469 (avg. 5.7)
1,635 (81.9%)
58 (2.9%)
Flatten Array Flatten Array
1,640
7,356 (avg. 4.5)
1,238 (75.5%)
135 (8.2%)
Conway's Game of Life Conway's Game of Life
274
1,143 (avg. 4.2)
154 (56.2%)
0 (0.0%)
Grep Grep
622
2,722 (avg. 4.4)
336 (54.0%)
5 (0.8%)
Knapsack Knapsack
864
3,866 (avg. 4.5)
510 (59.0%)
9 (1.0%)
Ledger Ledger
303
2,025 (avg. 6.7)
166 (54.8%)
7 (2.3%)
Matching Brackets Matching Brackets
720
2,611 (avg. 3.6)
516 (71.7%)
8 (1.1%)
Nucleotide Count Nucleotide Count
2,057
5,869 (avg. 2.9)
1,841 (89.5%)
89 (4.3%)
Pascal's Triangle Pascal's Triangle
741
1,860 (avg. 2.5)
519 (70.0%)
4 (0.5%)
Phone Number Phone Number
1,427
7,560 (avg. 5.3)
1,102 (77.2%)
24 (1.7%)
Pig Latin Pig Latin
2,642
10,971 (avg. 4.2)
1,454 (55.0%)
76 (2.9%)
Prime Factors Prime Factors
826
2,487 (avg. 3.0)
624 (75.5%)
11 (1.3%)
Relative Distance Relative Distance
32
180 (avg. 5.6)
15 (46.9%)
0 (0.0%)
Robot Name Robot Name
1,724
9,700 (avg. 5.6)
1,436 (83.3%)
137 (7.9%)
Run-Length Encoding Run-Length Encoding
597
2,242 (avg. 3.8)
421 (70.5%)
9 (1.5%)
Series Series
948
2,643 (avg. 2.8)
778 (82.1%)
11 (1.2%)
Square Root Square Root
439
1,269 (avg. 2.9)
347 (79.0%)
7 (1.6%)
Word Count Word Count
2,770
15,969 (avg. 5.8)
2,121 (76.6%)
212 (7.7%)
State Of Tic Tac Toe State Of Tic Tac Toe
210
1,371 (avg. 6.5)
124 (59.0%)
5 (2.4%)
Affine Cipher Affine Cipher
322
2,220 (avg. 6.9)
206 (64.0%)
3 (0.9%)
All Your Base All Your Base
457
2,158 (avg. 4.7)
307 (67.2%)
2 (0.4%)
Alphametics Alphametics
507
2,074 (avg. 4.1)
197 (38.9%)
3 (0.6%)
Bank Account Bank Account
1,506
8,334 (avg. 5.5)
1,076 (71.4%)
89 (5.9%)
Binary Search Binary Search
1,245
6,911 (avg. 5.6)
946 (76.0%)
93 (7.5%)
Bottle Song Bottle Song
642
6,183 (avg. 9.6)
415 (64.6%)
18 (2.8%)
Bowling Bowling
871
6,504 (avg. 7.5)
386 (44.3%)
11 (1.3%)
ETL ETL
1,744
2,555 (avg. 1.5)
1,599 (91.7%)
128 (7.3%)
Food Chain Food Chain
831
3,091 (avg. 3.7)
560 (67.4%)
10 (1.2%)
Grade School Grade School
750
2,418 (avg. 3.2)
552 (73.6%)
21 (2.8%)
House House
902
3,326 (avg. 3.7)
660 (73.2%)
9 (1.0%)
Linked List Linked List
1,327
5,673 (avg. 4.3)
947 (71.4%)
75 (5.7%)
Minesweeper Minesweeper
788
2,844 (avg. 3.6)
512 (65.0%)
9 (1.1%)
Parallel Letter Frequency Parallel Letter Frequency
679
3,187 (avg. 4.7)
428 (63.0%)
12 (1.8%)
Queen Attack Queen Attack
1,987
7,506 (avg. 3.8)
723 (36.4%)
33 (1.7%)
Rail Fence Cipher Rail Fence Cipher
326
1,331 (avg. 4.1)
194 (59.5%)
1 (0.3%)
REST API REST API
618
2,845 (avg. 4.6)
145 (23.5%)
4 (0.6%)
Robot Simulator Robot Simulator
750
2,440 (avg. 3.3)
474 (63.2%)
10 (1.3%)
Roman Numerals Roman Numerals
1,106
3,297 (avg. 3.0)
821 (74.2%)
15 (1.4%)
Spiral Matrix Spiral Matrix
539
1,299 (avg. 2.4)
330 (61.2%)
6 (1.1%)
Tournament Tournament
598
2,709 (avg. 4.5)
313 (52.3%)
10 (1.7%)
Transpose Transpose
498
2,386 (avg. 4.8)
267 (53.6%)
2 (0.4%)
Wordy Wordy
524
2,347 (avg. 4.5)
303 (57.8%)
6 (1.1%)
Anagram Anagram
3,073
9,778 (avg. 3.2)
2,209 (71.9%)
111 (3.6%)
Binary Search Tree Binary Search Tree
581
2,370 (avg. 4.1)
326 (56.1%)
7 (1.2%)
Clock Clock
486
1,957 (avg. 4.0)
328 (67.5%)
3 (0.6%)
Crypto Square Crypto Square
404
1,647 (avg. 4.1)
276 (68.3%)
2 (0.5%)
Dominoes Dominoes
1,027
3,056 (avg. 3.0)
256 (24.9%)
9 (0.9%)
Go Counting Go Counting
453
1,378 (avg. 3.0)
161 (35.5%)
0 (0.0%)
Markdown Markdown
852
1,812 (avg. 2.1)
344 (40.4%)
14 (1.6%)
Meetup Meetup
852
2,275 (avg. 2.7)
671 (78.8%)
12 (1.4%)
Poker Poker
690
2,315 (avg. 3.4)
202 (29.3%)
4 (0.6%)
SGF Parsing SGF Parsing
108
1,347 (avg. 12.5)
60 (55.6%)
2 (1.9%)
Simple Linked List Simple Linked List
671
3,501 (avg. 5.2)
410 (61.1%)
9 (1.3%)
Sublist Sublist
424
1,458 (avg. 3.4)
278 (65.6%)
0 (0.0%)
Tree Building Tree Building
280
587 (avg. 2.1)
124 (44.3%)
2 (0.7%)
Two Bucket Two Bucket
335
946 (avg. 2.8)
145 (43.3%)
3 (0.9%)
Word Search Word Search
818
2,298 (avg. 2.8)
247 (30.2%)
5 (0.6%)
Zebra Puzzle Zebra Puzzle
2,210
1,928 (avg. 0.9)
378 (17.1%)
6 (0.3%)
Zipper Zipper
258
733 (avg. 2.8)
113 (43.8%)
0 (0.0%)
Book Store Book Store
496
1,468 (avg. 3.0)
175 (35.3%)
5 (1.0%)
Change Change
467
2,372 (avg. 5.1)
192 (41.1%)
4 (0.9%)
Circular Buffer Circular Buffer
520
1,843 (avg. 3.5)
314 (60.4%)
4 (0.8%)
Complex Numbers Complex Numbers
526
1,699 (avg. 3.2)
327 (62.2%)
11 (2.1%)
Connect Connect
300
1,563 (avg. 5.2)
156 (52.0%)
7 (2.3%)
Hangman Hangman
283
703 (avg. 2.5)
70 (24.7%)
5 (1.8%)
List Ops List Ops
449
1,925 (avg. 4.3)
245 (54.6%)
8 (1.8%)
Mazy Mice Mazy Mice
92
555 (avg. 6.0)
43 (46.7%)
1 (1.1%)
OCR Numbers OCR Numbers
343
675 (avg. 2.0)
178 (51.9%)
3 (0.9%)
Palindrome Products Palindrome Products
410
1,171 (avg. 2.9)
215 (52.4%)
3 (0.7%)
POV POV
103
665 (avg. 6.5)
55 (53.4%)
1 (1.0%)
Rational Numbers Rational Numbers
410
2,375 (avg. 5.8)
224 (54.6%)
4 (1.0%)
React React
163
796 (avg. 4.9)
55 (33.7%)
1 (0.6%)
Rectangles Rectangles
313
807 (avg. 2.6)
158 (50.5%)
3 (1.0%)
Simple Cipher Simple Cipher
471
1,478 (avg. 3.1)
304 (64.5%)
7 (1.5%)
Forth Forth
467
1,547 (avg. 3.3)
188 (40.3%)
11 (2.4%)
Pythagorean Triplet Pythagorean Triplet
983
6,145 (avg. 6.3)
426 (43.3%)
6 (0.6%)
Custom Set Custom Set
469
1,592 (avg. 3.4)
217 (46.3%)
2 (0.4%)
Satellite Satellite
353
824 (avg. 2.3)
136 (38.5%)
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
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PaaS I/O PaaS I/O
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Piecing It Together Piecing It Together
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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

Learn More

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

Current version: d72915a0627b2696e95eed78a80fec3c8925d096 (Takes up to 10 mins to deploy)

Total Test Runner Runs
3,423,054
Test Run Pass Rate
17.3% (592576)
Test Run Fail Rate
37.9% (1297041)
Test Run Error Rate
44.8% (1533437)

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: 72671230d057b5d97b6a89c41440b20f9b1a379d (Takes up to 10 mins to deploy)

Total Representer Runs
733,631
Total Representation Comments Made
47,268
Feedback Given Frequency
6.4%

Analyzer

Learn More

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

Current version: ad7b27d23d2aba8d9fbb16792e5a87b63919d2db (Takes up to 10 mins to deploy)

Total Analyzer Runs
449,212
Total Analysis Comments Made
261,202
Feedback Given Frequency
3.5%