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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
170,542
Submissions
2,202,879
Mentoring Discussions
15,147

The Java track needs attention ⚠️

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.
25 concepts being taught
Ba
Basics
30,750 learnt
Bo
Booleans
17,015 learnt
Ar
Arrays
7,122 learnt
Fo
For Loops
7,122 learnt
Fo
For-Each Loops
7,122 learnt
Ge
Generic Types
4,789 learnt
Li
Lists
4,789 learnt
Ex
Exceptions
1,109 learnt
Ch
Chars
4,768 learnt
Cl
Classes
4,397 learnt
Co
Constructors
3,287 learnt
In
Interfaces
2,356 learnt
If
If-Else Statements
7,470 learnt
Nu
Numbers
7,470 learnt
St
Strings
11,728 learnt
Te
Ternary Operators
3,953 learnt
Sw
Switch Statements
2,858 learnt
In
Inheritance
2,531 learnt
En
Enums
711 learnt
Nu
Nullability
1,052 learnt
Ra
Randomness
664 learnt
Da
Date-Time
674 learnt
Me
Method Overloading
439 learnt
Bi
Bit Manipulation
514 learnt
Se
Sets
113 learnt
21 active learning exercises
Started
Attempts
Completions
Mentoring requests
Cook your lasagna Cook your lasagna
49,829
261,312 (avg. 5.2)
30,750 (61.7%)
443 (0.9%)
Annalyn's Infiltration Annalyn's Infiltration
22,525
195,637 (avg. 8.7)
17,015 (75.5%)
287 (1.3%)
Bird Watcher Bird Watcher
8,333
112,126 (avg. 13.5)
7,122 (85.5%)
146 (1.8%)
Karl's Languages Karl's Languages
5,161
25,652 (avg. 5.0)
4,789 (92.8%)
37 (0.7%)
Calculator Conundrum Calculator Conundrum
1,326
17,772 (avg. 13.4)
1,109 (83.6%)
24 (1.8%)
Squeaky Clean Squeaky Clean
7,969
121,747 (avg. 15.3)
4,768 (59.8%)
220 (2.8%)
Elon's Toy Car Elon's Toy Car
4,691
35,130 (avg. 7.5)
4,397 (93.7%)
57 (1.2%)
Need for Speed Need for Speed
3,638
35,548 (avg. 9.8)
3,287 (90.4%)
46 (1.3%)
Remote Control Competition Remote Control Competition
3,050
32,242 (avg. 10.6)
2,356 (77.2%)
49 (1.6%)
Cars, Assemble! Cars, Assemble!
8,261
59,303 (avg. 7.2)
7,470 (90.4%)
110 (1.3%)
Log Levels Log Levels
18,569
162,203 (avg. 8.7)
11,728 (63.2%)
253 (1.4%)
Salary Calculator Salary Calculator
4,245
22,794 (avg. 5.4)
3,953 (93.1%)
35 (0.8%)
Football Match Reports Football Match Reports
2,931
11,336 (avg. 3.9)
2,858 (97.5%)
28 (1.0%)
Wizards and Warriors Wizards and Warriors
2,718
15,232 (avg. 5.6)
2,531 (93.1%)
27 (1.0%)
Logs, Logs, Logs! Logs, Logs, Logs!
848
8,111 (avg. 9.6)
711 (83.8%)
11 (1.3%)
Tim from Marketing Tim from Marketing
1,130
7,529 (avg. 6.7)
1,052 (93.1%)
18 (1.6%)
Captain's Log Captain's Log
709
4,451 (avg. 6.3)
664 (93.7%)
5 (0.7%)
Booking Up For Beauty Booking Up For Beauty
828
11,878 (avg. 14.3)
674 (81.4%)
11 (1.3%)
Wizards and Warriors 2 Wizards and Warriors 2
478
3,925 (avg. 8.2)
439 (91.8%)
8 (1.7%)
Secrets Secrets
621
3,655 (avg. 5.9)
514 (82.8%)
1 (0.2%)
Gotta Snatch 'Em All Gotta Snatch 'Em All
161
1,928 (avg. 12.0)
113 (70.2%)
3 (1.9%)
1 deprecated learning exercises
Started
Attempts
Completions
Mentoring requests
Play Your Cards! Play Your Cards!
8,676
85,657 (avg. 9.9)
6,839 (78.8%)
118 (1.4%)

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.

Synced primary repo: c1f9ee4237ba88a9ac0058c8ef4bcffd0d40fea9 (Updates should be instant)

Next goal: Implement 128 practice exercises. Find out more.
125 active practice exercises
Started
Attempts
Completions
Mentoring requests
Hello World Hello World
115,572
241,500 (avg. 2.1)
75,261 (65.1%)
40 (0.0%)
Leap Leap
3,842
9,151 (avg. 2.4)
3,100 (80.7%)
52 (1.4%)
Reverse String Reverse String
12,465
35,506 (avg. 2.8)
10,354 (83.1%)
291 (2.3%)
Two Fer Two Fer
20,871
64,572 (avg. 3.1)
16,280 (78.0%)
3,902 (18.7%)
Armstrong Numbers Armstrong Numbers
4,290
9,338 (avg. 2.2)
3,247 (75.7%)
97 (2.3%)
Darts Darts
4,594
14,112 (avg. 3.1)
3,514 (76.5%)
42 (0.9%)
D&D Character D&D Character
2,931
16,778 (avg. 5.7)
2,012 (68.6%)
38 (1.3%)
Grains Grains
2,776
18,696 (avg. 6.7)
2,209 (79.6%)
36 (1.3%)
High Scores High Scores
682
6,179 (avg. 9.1)
560 (82.1%)
15 (2.2%)
Resistor Color Resistor Color
4,898
15,321 (avg. 3.1)
3,792 (77.4%)
61 (1.2%)
Resistor Color Duo Resistor Color Duo
3,169
8,664 (avg. 2.7)
2,587 (81.6%)
31 (1.0%)
Resistor Color Trio Resistor Color Trio
248
3,705 (avg. 14.9)
207 (83.5%)
11 (4.4%)
RNA Transcription RNA Transcription
5,303
11,710 (avg. 2.2)
4,395 (82.9%)
219 (4.1%)
Acronym Acronym
3,210
9,943 (avg. 3.1)
2,499 (77.9%)
74 (2.3%)
Difference of Squares Difference of Squares
5,537
18,222 (avg. 3.3)
4,789 (86.5%)
698 (12.6%)
Gigasecond Gigasecond
7,565
17,179 (avg. 2.3)
5,283 (69.8%)
1,343 (17.8%)
Hamming Hamming
7,307
25,215 (avg. 3.5)
5,973 (81.7%)
1,482 (20.3%)
Micro Blog Micro Blog
5,226
30,222 (avg. 5.8)
3,083 (59.0%)
74 (1.4%)
Pangram Pangram
4,257
8,765 (avg. 2.1)
3,495 (82.1%)
159 (3.7%)
Perfect Numbers Perfect Numbers
2,682
8,816 (avg. 3.3)
1,712 (63.8%)
39 (1.5%)
Eliud's Eggs Eliud's Eggs
276
1,017 (avg. 3.7)
241 (87.3%)
3 (1.1%)
Protein Translation Protein Translation
2,656
8,313 (avg. 3.1)
2,068 (77.9%)
38 (1.4%)
Raindrops Raindrops
7,071
17,431 (avg. 2.5)
5,895 (83.4%)
246 (3.5%)
Say Say
1,657
7,357 (avg. 4.4)
524 (31.6%)
27 (1.6%)
Scrabble Score Scrabble Score
5,347
19,164 (avg. 3.6)
4,484 (83.9%)
1,077 (20.1%)
Secret Handshake Secret Handshake
3,461
15,648 (avg. 4.5)
2,596 (75.0%)
461 (13.3%)
Space Age Space Age
3,401
5,964 (avg. 1.8)
2,560 (75.3%)
57 (1.7%)
Collatz Conjecture Collatz Conjecture
916
2,477 (avg. 2.7)
750 (81.9%)
13 (1.4%)
Diamond Diamond
1,796
6,774 (avg. 3.8)
1,172 (65.3%)
27 (1.5%)
Error Handling Error Handling
1,031
6,542 (avg. 6.3)
517 (50.1%)
4 (0.4%)
ISBN Verifier ISBN Verifier
1,902
6,065 (avg. 3.2)
1,472 (77.4%)
32 (1.7%)
Isogram Isogram
4,273
14,958 (avg. 3.5)
3,391 (79.4%)
161 (3.8%)
Killer Sudoku Helper Killer Sudoku Helper
107
659 (avg. 6.2)
58 (54.2%)
4 (3.7%)
Kindergarten Garden Kindergarten Garden
726
1,386 (avg. 1.9)
520 (71.6%)
6 (0.8%)
Largest Series Product Largest Series Product
1,376
5,728 (avg. 4.2)
1,093 (79.4%)
14 (1.0%)
Luhn Luhn
1,969
7,738 (avg. 3.9)
1,513 (76.8%)
39 (2.0%)
Matrix Matrix
2,724
13,225 (avg. 4.9)
2,046 (75.1%)
310 (11.4%)
Nth Prime Nth Prime
992
2,796 (avg. 2.8)
738 (74.4%)
11 (1.1%)
Proverb Proverb
2,390
6,216 (avg. 2.6)
1,905 (79.7%)
28 (1.2%)
Rotational Cipher Rotational Cipher
2,066
10,013 (avg. 4.8)
1,726 (83.5%)
219 (10.6%)
Saddle Points Saddle Points
1,481
5,831 (avg. 3.9)
987 (66.6%)
156 (10.5%)
Sieve Sieve
1,079
2,292 (avg. 2.1)
839 (77.8%)
19 (1.8%)
Sum of Multiples Sum of Multiples
1,621
4,537 (avg. 2.8)
1,168 (72.1%)
29 (1.8%)
Triangle Triangle
2,516
9,661 (avg. 3.8)
2,143 (85.2%)
255 (10.1%)
Twelve Days Twelve Days
2,344
12,245 (avg. 5.2)
1,762 (75.2%)
28 (1.2%)
Variable Length Quantity Variable Length Quantity
450
869 (avg. 1.9)
213 (47.3%)
1 (0.2%)
Yacht Yacht
1,307
4,678 (avg. 3.6)
831 (63.6%)
27 (2.1%)
Allergies Allergies
1,012
3,011 (avg. 3.0)
781 (77.2%)
21 (2.1%)
Atbash Cipher Atbash Cipher
545
2,056 (avg. 3.8)
412 (75.6%)
4 (0.7%)
Bob Bob
1,730
8,595 (avg. 5.0)
1,412 (81.6%)
52 (3.0%)
Flatten Array Flatten Array
1,403
6,039 (avg. 4.3)
1,061 (75.6%)
131 (9.3%)
Grep Grep
445
1,426 (avg. 3.2)
212 (47.6%)
5 (1.1%)
Knapsack Knapsack
612
2,601 (avg. 4.3)
346 (56.5%)
9 (1.5%)
Ledger Ledger
141
547 (avg. 3.9)
63 (44.7%)
5 (3.5%)
Matching Brackets Matching Brackets
505
1,596 (avg. 3.2)
353 (69.9%)
5 (1.0%)
Nucleotide Count Nucleotide Count
1,879
4,935 (avg. 2.6)
1,693 (90.1%)
87 (4.6%)
Pascal's Triangle Pascal's Triangle
587
1,187 (avg. 2.0)
398 (67.8%)
3 (0.5%)
Phone Number Phone Number
1,240
5,582 (avg. 4.5)
970 (78.2%)
22 (1.8%)
Pig Latin Pig Latin
2,487
9,512 (avg. 3.8)
1,341 (53.9%)
74 (3.0%)
Prime Factors Prime Factors
674
1,798 (avg. 2.7)
500 (74.2%)
9 (1.3%)
Robot Name Robot Name
1,581
8,860 (avg. 5.6)
1,322 (83.6%)
136 (8.6%)
Run-Length Encoding Run-Length Encoding
467
1,516 (avg. 3.2)
314 (67.2%)
9 (1.9%)
Series Series
812
2,005 (avg. 2.5)
668 (82.3%)
9 (1.1%)
Square Root Square Root
221
655 (avg. 3.0)
167 (75.6%)
5 (2.3%)
Word Count Word Count
2,610
14,551 (avg. 5.6)
2,004 (76.8%)
213 (8.2%)
State Of Tic Tac Toe State Of Tic Tac Toe
47
311 (avg. 6.6)
25 (53.2%)
0 (0.0%)
Affine Cipher Affine Cipher
232
1,071 (avg. 4.6)
134 (57.8%)
3 (1.3%)
All Your Base All Your Base
347
1,133 (avg. 3.3)
213 (61.4%)
1 (0.3%)
Alphametics Alphametics
411
1,200 (avg. 2.9)
147 (35.8%)
3 (0.7%)
Bank Account Bank Account
1,277
7,115 (avg. 5.6)
908 (71.1%)
87 (6.8%)
Binary Search Binary Search
1,061
5,760 (avg. 5.4)
817 (77.0%)
89 (8.4%)
Bottle Song Bottle Song
443
4,351 (avg. 9.8)
281 (63.4%)
14 (3.2%)
Bowling Bowling
750
4,713 (avg. 6.3)
325 (43.3%)
11 (1.5%)
ETL ETL
1,632
2,267 (avg. 1.4)
1,505 (92.2%)
128 (7.8%)
Food Chain Food Chain
721
2,375 (avg. 3.3)
489 (67.8%)
10 (1.4%)
Grade School Grade School
635
1,624 (avg. 2.6)
465 (73.2%)
19 (3.0%)
House House
827
2,962 (avg. 3.6)
603 (72.9%)
9 (1.1%)
Linked List Linked List
1,184
4,916 (avg. 4.2)
865 (73.1%)
73 (6.2%)
Minesweeper Minesweeper
678
2,284 (avg. 3.4)
437 (64.5%)
7 (1.0%)
Parallel Letter Frequency Parallel Letter Frequency
485
1,967 (avg. 4.1)
300 (61.9%)
8 (1.6%)
Queen Attack Queen Attack
1,899
6,985 (avg. 3.7)
653 (34.4%)
30 (1.6%)
Rail Fence Cipher Rail Fence Cipher
255
729 (avg. 2.9)
140 (54.9%)
0 (0.0%)
REST API REST API
453
1,130 (avg. 2.5)
94 (20.8%)
2 (0.4%)
Robot Simulator Robot Simulator
641
1,930 (avg. 3.0)
387 (60.4%)
9 (1.4%)
Roman Numerals Roman Numerals
983
2,618 (avg. 2.7)
731 (74.4%)
12 (1.2%)
Spiral Matrix Spiral Matrix
449
909 (avg. 2.0)
260 (57.9%)
3 (0.7%)
Tournament Tournament
450
1,581 (avg. 3.5)
228 (50.7%)
4 (0.9%)
Transpose Transpose
423
1,726 (avg. 4.1)
219 (51.8%)
2 (0.5%)
Wordy Wordy
452
1,606 (avg. 3.6)
255 (56.4%)
5 (1.1%)
Anagram Anagram
2,980
9,258 (avg. 3.1)
2,138 (71.7%)
111 (3.7%)
Binary Search Tree Binary Search Tree
481
1,600 (avg. 3.3)
265 (55.1%)
6 (1.2%)
Clock Clock
411
1,481 (avg. 3.6)
266 (64.7%)
1 (0.2%)
Crypto Square Crypto Square
345
1,135 (avg. 3.3)
227 (65.8%)
2 (0.6%)
Dominoes Dominoes
963
2,453 (avg. 2.5)
224 (23.3%)
9 (0.9%)
Go Counting Go Counting
403
843 (avg. 2.1)
130 (32.3%)
0 (0.0%)
Markdown Markdown
757
1,426 (avg. 1.9)
287 (37.9%)
13 (1.7%)
Meetup Meetup
763
1,800 (avg. 2.4)
616 (80.7%)
10 (1.3%)
Poker Poker
620
1,641 (avg. 2.6)
170 (27.4%)
2 (0.3%)
SGF Parsing SGF Parsing
63
566 (avg. 9.0)
35 (55.6%)
2 (3.2%)
Simple Linked List Simple Linked List
563
2,641 (avg. 4.7)
338 (60.0%)
8 (1.4%)
Sublist Sublist
351
1,139 (avg. 3.2)
226 (64.4%)
0 (0.0%)
Tree Building Tree Building
223
379 (avg. 1.7)
92 (41.3%)
2 (0.9%)
Two Bucket Two Bucket
275
635 (avg. 2.3)
111 (40.4%)
3 (1.1%)
Word Search Word Search
743
1,790 (avg. 2.4)
212 (28.5%)
4 (0.5%)
Zebra Puzzle Zebra Puzzle
850
744 (avg. 0.9)
200 (23.5%)
1 (0.1%)
Zipper Zipper
203
473 (avg. 2.3)
81 (39.9%)
0 (0.0%)
Book Store Book Store
371
833 (avg. 2.2)
129 (34.8%)
5 (1.3%)
Change Change
365
1,170 (avg. 3.2)
139 (38.1%)
2 (0.5%)
Circular Buffer Circular Buffer
424
1,273 (avg. 3.0)
247 (58.3%)
2 (0.5%)
Complex Numbers Complex Numbers
380
1,047 (avg. 2.8)
228 (60.0%)
5 (1.3%)
Connect Connect
261
1,207 (avg. 4.6)
128 (49.0%)
7 (2.7%)
Hangman Hangman
209
423 (avg. 2.0)
46 (22.0%)
5 (2.4%)
List Ops List Ops
340
1,298 (avg. 3.8)
183 (53.8%)
6 (1.8%)
Mazy Mice Mazy Mice
33
146 (avg. 4.4)
11 (33.3%)
0 (0.0%)
OCR Numbers OCR Numbers
297
440 (avg. 1.5)
143 (48.1%)
2 (0.7%)
Palindrome Products Palindrome Products
331
865 (avg. 2.6)
168 (50.8%)
2 (0.6%)
POV POV
59
199 (avg. 3.4)
28 (47.5%)
1 (1.7%)
Rational Numbers Rational Numbers
305
1,587 (avg. 5.2)
162 (53.1%)
4 (1.3%)
React React
69
254 (avg. 3.7)
21 (30.4%)
0 (0.0%)
Rectangles Rectangles
255
564 (avg. 2.2)
123 (48.2%)
3 (1.2%)
Simple Cipher Simple Cipher
410
1,088 (avg. 2.7)
260 (63.4%)
5 (1.2%)
Forth Forth
417
1,130 (avg. 2.7)
157 (37.6%)
11 (2.6%)
Pythagorean Triplet Pythagorean Triplet
868
5,495 (avg. 6.3)
369 (42.5%)
5 (0.6%)
Custom Set Custom Set
350
899 (avg. 2.6)
156 (44.6%)
1 (0.3%)
Satellite Satellite
218
511 (avg. 2.3)
88 (40.4%)
2 (0.9%)
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
3,362 (avg. 3.9)
662 (76.4%)
15 (1.7%)
Binary Binary
136
180 (avg. 1.3)
133 (97.8%)
6 (4.4%)
Diffie-Hellman Diffie-Hellman
228
324 (avg. 1.4)
117 (51.3%)
2 (0.9%)
Hexadecimal Hexadecimal
58
72 (avg. 1.2)
55 (94.8%)
7 (12.1%)
Octal Octal
59
69 (avg. 1.2)
56 (94.9%)
2 (3.4%)
Strain Strain
111
137 (avg. 1.2)
107 (96.4%)
5 (4.5%)
Trinary Trinary
71
83 (avg. 1.2)
68 (95.8%)
1 (1.4%)
3 unimplemented practice exercises
Conway's Game of Life Conway's Game of Life
View dataThe link opens in a new window or tab
DOT DSL DOT DSL
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
1 foregone practice exercise
Lens Person Lens Person
View dataThe link opens in a new window or tab

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: 280ae10761abe08b8930854acb6c30fa51fb809a (Takes up to 10 mins to deploy)

Total Test Runner Runs
2,134,998
Test Run Pass Rate
18.4% (391916)
Test Run Fail Rate
36.5% (778575)
Test Run Error Rate
45.2% (964507)

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: eeef81d903415f8612eb8dd37a400a5af2686114 (Takes up to 10 mins to deploy)

Total Representer Runs
553,971
Total Representation Comments Made
4
Feedback Given Frequency
0.0%

Analyzer

Learn More

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

Current version: d2373ea2c60b2ddfb9e470db2ff5acc2542570ae (Takes up to 10 mins to deploy)

Total Analyzer Runs
270,261
Total Analysis Comments Made
125,480
Feedback Given Frequency
2.5%