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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
220,622
Submissions
3,565,652
Mentoring Discussions
16,557

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
45,564 learnt
Bo
Booleans
25,859 learnt
Ar
Arrays
12,197 learnt
Fo
For Loops
12,197 learnt
Fo
For-Each Loops
12,197 learnt
Ge
Generic Types
8,643 learnt
Li
Lists
8,643 learnt
Ex
Exceptions
3,781 learnt
Ch
Chars
8,412 learnt
Cl
Classes
8,126 learnt
Co
Constructors
5,982 learnt
In
Interfaces
4,462 learnt
If
If-Else Statements
12,928 learnt
Nu
Numbers
12,928 learnt
St
Strings
17,575 learnt
Te
Ternary Operators
7,199 learnt
Sw
Switch Statements
5,252 learnt
In
Inheritance
4,758 learnt
En
Enums
2,462 learnt
Nu
Nullability
4,037 learnt
Ra
Randomness
2,715 learnt
Da
Date-Time
2,752 learnt
Me
Method Overloading
2,041 learnt
Bi
Bit Manipulation
2,447 learnt
Se
Sets
1,810 learnt
Ma
Maps
669 learnt
22 active learning exercises
Started
Attempts
Completions
Mentoring requests
Cook Your Lasagna Cook Your Lasagna
74,430
409,639 (avg. 5.5)
45,564 (61.2%)
476 (0.6%)
Annalyn's Infiltration Annalyn's Infiltration
34,672
329,375 (avg. 9.5)
25,859 (74.6%)
303 (0.9%)
Bird Watcher Bird Watcher
14,645
201,613 (avg. 13.8)
12,197 (83.3%)
276 (1.9%)
Karl's Languages Karl's Languages
9,506
52,531 (avg. 5.5)
8,643 (90.9%)
72 (0.8%)
Calculator Conundrum Calculator Conundrum
4,597
64,026 (avg. 13.9)
3,781 (82.2%)
70 (1.5%)
Squeaky Clean Squeaky Clean
13,272
201,518 (avg. 15.2)
8,412 (63.4%)
399 (3.0%)
Jedlik's Toy Car Jedlik's Toy Car
8,880
75,582 (avg. 8.5)
8,126 (91.5%)
95 (1.1%)
Need for Speed Need for Speed
6,816
82,018 (avg. 12.0)
5,982 (87.8%)
63 (0.9%)
Remote Control Competition Remote Control Competition
5,625
61,308 (avg. 10.9)
4,462 (79.3%)
80 (1.4%)
Cars, Assemble! Cars, Assemble!
14,417
110,229 (avg. 7.6)
12,928 (89.7%)
268 (1.9%)
Log Levels Log Levels
27,367
247,353 (avg. 9.0)
17,575 (64.2%)
288 (1.1%)
Salary Calculator Salary Calculator
7,732
45,223 (avg. 5.8)
7,199 (93.1%)
38 (0.5%)
Football Match Reports Football Match Reports
5,413
23,116 (avg. 4.3)
5,252 (97.0%)
38 (0.7%)
Wizards and Warriors Wizards and Warriors
5,234
36,693 (avg. 7.0)
4,758 (90.9%)
35 (0.7%)
Logs, Logs, Logs! Logs, Logs, Logs!
2,871
29,491 (avg. 10.3)
2,462 (85.8%)
36 (1.3%)
Tim from Marketing Tim from Marketing
4,290
28,828 (avg. 6.7)
4,037 (94.1%)
54 (1.3%)
Captain's Log Captain's Log
2,899
18,889 (avg. 6.5)
2,715 (93.7%)
14 (0.5%)
Booking Up For Beauty Booking Up For Beauty
3,341
47,410 (avg. 14.2)
2,752 (82.4%)
31 (0.9%)
Wizards and Warriors 2 Wizards and Warriors 2
2,252
19,277 (avg. 8.6)
2,041 (90.6%)
18 (0.8%)
Secrets Secrets
2,821
16,074 (avg. 5.7)
2,447 (86.7%)
4 (0.1%)
Gotta Snatch 'Em All Gotta Snatch 'Em All
2,139
27,031 (avg. 12.6)
1,810 (84.6%)
30 (1.4%)
International Calling Connoisseur International Calling Connoisseur
765
8,573 (avg. 11.2)
669 (87.5%)
6 (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: 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
163,790
340,809 (avg. 2.1)
104,337 (63.7%)
40 (0.0%)
Leap Leap
6,171
21,110 (avg. 3.4)
5,028 (81.5%)
92 (1.5%)
Reverse String Reverse String
14,364
42,301 (avg. 2.9)
12,000 (83.5%)
317 (2.2%)
Two Fer Two Fer
22,603
71,823 (avg. 3.2)
17,873 (79.1%)
3,919 (17.3%)
Armstrong Numbers Armstrong Numbers
6,033
18,803 (avg. 3.1)
4,741 (78.6%)
129 (2.1%)
Darts Darts
6,130
21,012 (avg. 3.4)
4,795 (78.2%)
60 (1.0%)
D&D Character D&D Character
4,054
31,374 (avg. 7.7)
2,826 (69.7%)
61 (1.5%)
DOT DSL DOT DSL
753
3,353 (avg. 4.5)
454 (60.3%)
5 (0.7%)
Grains Grains
3,975
30,413 (avg. 7.7)
3,211 (80.8%)
47 (1.2%)
High Scores High Scores
1,831
15,368 (avg. 8.4)
1,488 (81.3%)
31 (1.7%)
Resistor Color Resistor Color
5,905
20,829 (avg. 3.5)
4,704 (79.7%)
69 (1.2%)
Resistor Color Duo Resistor Color Duo
4,068
12,725 (avg. 3.1)
3,407 (83.8%)
41 (1.0%)
Resistor Color Trio Resistor Color Trio
1,104
13,224 (avg. 12.0)
932 (84.4%)
30 (2.7%)
RNA Transcription RNA Transcription
6,143
15,236 (avg. 2.5)
5,162 (84.0%)
234 (3.8%)
Acronym Acronym
4,069
15,933 (avg. 3.9)
3,224 (79.2%)
90 (2.2%)
Difference of Squares Difference of Squares
6,394
21,570 (avg. 3.4)
5,581 (87.3%)
706 (11.0%)
Gigasecond Gigasecond
8,151
19,086 (avg. 2.3)
5,806 (71.2%)
1,344 (16.5%)
Hamming Hamming
8,082
29,461 (avg. 3.6)
6,647 (82.2%)
1,490 (18.4%)
Micro Blog Micro Blog
6,098
34,925 (avg. 5.7)
3,686 (60.4%)
87 (1.4%)
Pangram Pangram
5,042
12,434 (avg. 2.5)
4,187 (83.0%)
169 (3.4%)
Perfect Numbers Perfect Numbers
3,215
11,821 (avg. 3.7)
2,191 (68.1%)
45 (1.4%)
Eliud's Eggs Eliud's Eggs
849
2,815 (avg. 3.3)
759 (89.4%)
9 (1.1%)
Protein Translation Protein Translation
3,295
14,819 (avg. 4.5)
2,593 (78.7%)
48 (1.5%)
Raindrops Raindrops
7,802
20,208 (avg. 2.6)
6,557 (84.0%)
252 (3.2%)
Say Say
2,274
13,998 (avg. 6.2)
929 (40.9%)
37 (1.6%)
Scrabble Score Scrabble Score
5,910
21,436 (avg. 3.6)
4,988 (84.4%)
1,080 (18.3%)
Secret Handshake Secret Handshake
3,920
19,104 (avg. 4.9)
2,991 (76.3%)
464 (11.8%)
Space Age Space Age
4,105
8,814 (avg. 2.1)
3,147 (76.7%)
60 (1.5%)
Collatz Conjecture Collatz Conjecture
1,668
6,301 (avg. 3.8)
1,388 (83.2%)
28 (1.7%)
Diamond Diamond
2,436
12,072 (avg. 5.0)
1,612 (66.2%)
49 (2.0%)
Error Handling Error Handling
1,578
11,488 (avg. 7.3)
891 (56.5%)
5 (0.3%)
ISBN Verifier ISBN Verifier
2,446
10,761 (avg. 4.4)
1,906 (77.9%)
40 (1.6%)
Isogram Isogram
4,788
17,826 (avg. 3.7)
3,858 (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
1,320
4,621 (avg. 3.5)
1,014 (76.8%)
17 (1.3%)
Proverb Proverb
2,696
7,751 (avg. 2.9)
2,177 (80.7%)
32 (1.2%)
Rotational Cipher Rotational Cipher
2,323
11,568 (avg. 5.0)
1,956 (84.2%)
224 (9.6%)
Saddle Points Saddle Points
1,716
7,453 (avg. 4.3)
1,170 (68.2%)
160 (9.3%)
Sieve Sieve
1,351
3,661 (avg. 2.7)
1,077 (79.7%)
23 (1.7%)
Sum of Multiples Sum of Multiples
1,947
6,704 (avg. 3.4)
1,416 (72.7%)
36 (1.8%)
Triangle Triangle
2,780
11,019 (avg. 4.0)
2,366 (85.1%)
258 (9.3%)
Twelve Days Twelve Days
2,598
13,967 (avg. 5.4)
1,953 (75.2%)
33 (1.3%)
Variable Length Quantity Variable Length Quantity
613
2,057 (avg. 3.4)
315 (51.4%)
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
745
3,865 (avg. 5.2)
590 (79.2%)
8 (1.1%)
Bob Bob
2,005
11,558 (avg. 5.8)
1,641 (81.8%)
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
868
3,882 (avg. 4.5)
512 (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
10,981 (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
81
597 (avg. 7.4)
34 (42.0%)
0 (0.0%)
Robot Name Robot Name
1,730
9,733 (avg. 5.6)
1,438 (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
952
2,654 (avg. 2.8)
782 (82.1%)
11 (1.2%)
Square Root Square Root
451
1,321 (avg. 2.9)
355 (78.7%)
7 (1.6%)
Word Count Word Count
2,775
15,983 (avg. 5.8)
2,125 (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
324
2,263 (avg. 7.0)
209 (64.5%)
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
1,250
6,922 (avg. 5.5)
951 (76.1%)
93 (7.4%)
Bottle Song Bottle Song
652
6,217 (avg. 9.5)
422 (64.7%)
18 (2.8%)
Bowling Bowling
878
6,539 (avg. 7.4)
389 (44.3%)
11 (1.3%)
ETL ETL
1,752
2,594 (avg. 1.5)
1,603 (91.5%)
128 (7.3%)
Food Chain Food Chain
839
3,139 (avg. 3.7)
566 (67.5%)
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
1,334
5,716 (avg. 4.3)
953 (71.4%)
75 (5.6%)
Minesweeper Minesweeper
794
2,848 (avg. 3.6)
516 (65.0%)
9 (1.1%)
Parallel Letter Frequency Parallel Letter Frequency
689
3,240 (avg. 4.7)
435 (63.1%)
13 (1.9%)
Piecing It Together Piecing It Together
1
0 (avg. 0.0)
0 (0.0%)
0 (0.0%)
Queen Attack Queen Attack
1,993
7,516 (avg. 3.8)
726 (36.4%)
33 (1.7%)
Rail Fence Cipher Rail Fence Cipher
329
1,334 (avg. 4.1)
197 (59.9%)
1 (0.3%)
REST API REST API
627
2,967 (avg. 4.7)
149 (23.8%)
4 (0.6%)
Robot Simulator Robot Simulator
755
2,450 (avg. 3.2)
476 (63.0%)
10 (1.3%)
Roman Numerals Roman Numerals
1,113
3,322 (avg. 3.0)
824 (74.0%)
15 (1.3%)
Spiral Matrix Spiral Matrix
546
1,308 (avg. 2.4)
334 (61.2%)
6 (1.1%)
Tournament Tournament
611
2,756 (avg. 4.5)
319 (52.2%)
10 (1.6%)
Transpose Transpose
502
2,400 (avg. 4.8)
269 (53.6%)
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
586
2,415 (avg. 4.1)
329 (56.1%)
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
853
2,278 (avg. 2.7)
672 (78.8%)
12 (1.4%)
Poker Poker
692
2,379 (avg. 3.4)
205 (29.6%)
4 (0.6%)
SGF Parsing SGF Parsing
112
1,637 (avg. 14.6)
62 (55.4%)
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
286
686 (avg. 2.4)
127 (44.4%)
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
2,325
2,087 (avg. 0.9)
394 (16.9%)
7 (0.3%)
Zipper Zipper
262
810 (avg. 3.1)
115 (43.9%)
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
1,934 (avg. 3.7)
317 (60.5%)
4 (0.8%)
Complex Numbers Complex Numbers
533
1,719 (avg. 3.2)
333 (62.5%)
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
681 (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
475
1,603 (avg. 3.4)
220 (46.3%)
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: d72915a0627b2696e95eed78a80fec3c8925d096 (Takes up to 10 mins to deploy)

Total Test Runner Runs
3,488,261
Test Run Pass Rate
17.3% (603282)
Test Run Fail Rate
37.9% (1322382)
Test Run Error Rate
44.8% (1562597)

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: 0f1cb34376a7cea236235291edbc8ffebd462b27 (Takes up to 10 mins to deploy)

Total Representer Runs
743,096
Total Representation Comments Made
49,526
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: bdf076b64e0ae5063a612a80f51fd9cb072670d0 (Takes up to 10 mins to deploy)

Total Analyzer Runs
458,633
Total Analysis Comments Made
269,233
Feedback Given Frequency
3.5%