1,074
students have developed their Ballerina skills on Exercism.

Students
1,074
Submissions
5,148
Mentoring Discussions
47

The Ballerina track needs attention ⚠️

Building

Build

Use your knowledge to build the Ballerina track itself

Build Test Runners

Learn More

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

Next goal: Get Test Runners to Version 2. Ballerina is currently utilising a Version 1 Test Runner. Find out more.

Usage statistics

Total Test Runner Runs
4,950
Test Run Pass Rate
35.0% (1731)
Test Run Fail Rate
54.4% (2695)
Test Run Error Rate
10.6% (524)

Build Analyzers

Learn More

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

Next goal: Build an Analyzer. Find out more.

Build Representers

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.

Next goal: Build a Representer. Find out more.

Create 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.

Next goal: Implement at least 50 practice exercises. Find out more.

Usage statistics

42 active practice exercises
Started
Attempts
Completions
Mentoring requests
Hello World Hello World
530
751 (avg. 1.4)
370 (69.8%)
0 (0.0%)
Calculator Service Calculator Service
234
1,027 (avg. 4.4)
136 (58.1%)
8 (3.4%)
Echo Service Echo Service
155
318 (avg. 2.1)
129 (83.2%)
4 (2.6%)
Service Error Handling Service Error Handling
113
613 (avg. 5.4)
95 (84.1%)
1 (0.9%)
Greeting Service Greeting Service
151
446 (avg. 3.0)
131 (86.8%)
7 (4.6%)
Hello World Service Hello World Service
178
275 (avg. 1.5)
143 (80.3%)
15 (8.4%)
Service Composition Service Composition
72
193 (avg. 2.7)
54 (75.0%)
0 (0.0%)
Service Invocation Service Invocation
12
15 (avg. 1.3)
7 (58.3%)
5 (41.7%)
CSV Fuel Allowance CSV Fuel Allowance
49
77 (avg. 1.6)
41 (83.7%)
0 (0.0%)
JSON Fuel Allowance JSON Fuel Allowance
54
87 (avg. 1.6)
43 (79.6%)
1 (1.9%)
XML Fuel Allowance XML Fuel Allowance
33
118 (avg. 3.6)
9 (27.3%)
0 (0.0%)
Monitor Rush Monitor Rush
38
61 (avg. 1.6)
36 (94.7%)
0 (0.0%)
The Cake is a Lie The Cake is a Lie
7
10 (avg. 1.4)
2 (28.6%)
0 (0.0%)
PaySwitch - Salary Converter PaySwitch - Salary Converter
2
2 (avg. 1.0)
1 (50.0%)
0 (0.0%)
Isogram Isogram
38
103 (avg. 2.7)
33 (86.8%)
0 (0.0%)
Raindrops Raindrops
31
69 (avg. 2.2)
28 (90.3%)
1 (3.2%)
Roman Numerals Roman Numerals
33
142 (avg. 4.3)
29 (87.9%)
1 (3.0%)
Space Age Space Age
30
107 (avg. 3.6)
29 (96.7%)
0 (0.0%)
Acronym Acronym
44
168 (avg. 3.8)
36 (81.8%)
1 (2.3%)
Sieve Sieve
7
7 (avg. 1.0)
5 (71.4%)
0 (0.0%)
Bob Bob
7
12 (avg. 1.7)
4 (57.1%)
0 (0.0%)
Collatz Conjecture Collatz Conjecture
8
33 (avg. 4.1)
5 (62.5%)
0 (0.0%)
Grains Grains
8
27 (avg. 3.4)
6 (75.0%)
0 (0.0%)
Knapsack Knapsack
4
3 (avg. 0.8)
2 (50.0%)
0 (0.0%)
Hamming Hamming
7
8 (avg. 1.1)
4 (57.1%)
0 (0.0%)
Difference Of Squares Difference Of Squares
11
18 (avg. 1.6)
10 (90.9%)
0 (0.0%)
Leap Leap
12
18 (avg. 1.5)
11 (91.7%)
0 (0.0%)
Darts Darts
8
13 (avg. 1.6)
7 (87.5%)
0 (0.0%)
Two Fer Two Fer
9
28 (avg. 3.1)
7 (77.8%)
0 (0.0%)
Pangram Pangram
9
34 (avg. 3.8)
7 (77.8%)
0 (0.0%)
Anagram Anagram
5
11 (avg. 2.2)
3 (60.0%)
1 (20.0%)
Protein Translation Protein Translation
6
6 (avg. 1.0)
3 (50.0%)
1 (16.7%)
ETL ETL
6
10 (avg. 1.7)
4 (66.7%)
1 (16.7%)
Two Bucket Two Bucket
3
4 (avg. 1.3)
2 (66.7%)
1 (33.3%)
Binary Search Binary Search
7
12 (avg. 1.7)
6 (85.7%)
0 (0.0%)
Linked List Linked List
5
3 (avg. 0.6)
2 (40.0%)
0 (0.0%)
Largest Series Product Largest Series Product
4
11 (avg. 2.8)
4 (100.0%)
0 (0.0%)
Robot Simulator Robot Simulator
3
2 (avg. 0.7)
2 (66.7%)
0 (0.0%)
Saddle Points Saddle Points
4
4 (avg. 1.0)
2 (50.0%)
1 (25.0%)
Sum Of Multiples Sum Of Multiples
5
14 (avg. 2.8)
4 (80.0%)
0 (0.0%)
Secret Handshake Secret Handshake
4
4 (avg. 1.0)
2 (50.0%)
0 (0.0%)
Yacht Yacht
4
59 (avg. 14.8)
3 (75.0%)
0 (0.0%)
2 deprecated practice exercises
Started
Attempts
Completions
Mentoring requests
Legacy Service Client Legacy Service Client
5
6 (avg. 1.2)
4 (80.0%)
2 (40.0%)
Order Management Order Management
1
1 (avg. 1.0)
1 (100.0%)
0 (0.0%)
98 unimplemented practice exercises
Affine Cipher Affine Cipher
All Your Base All Your Base
Allergies Allergies
Alphametics Alphametics
Armstrong Numbers Armstrong Numbers
Atbash Cipher Atbash Cipher
Bank Account Bank Account
Binary Search Tree Binary Search Tree
Book Store Book Store
Bottle Song Bottle Song
Bowling Bowling
Change Change
Circular Buffer Circular Buffer
Clock Clock
Complex Numbers Complex Numbers
Connect Connect
Crypto Square Crypto Square
Custom Set Custom Set
D&D Character D&D Character
DOT DSL DOT DSL
Diamond Diamond
Dominoes Dominoes
Flatten Array Flatten Array
Food Chain Food Chain
Forth Forth
Gigasecond Gigasecond
Go Counting Go Counting
Grade School Grade School
Grep Grep
Hangman Hangman
High Scores High Scores
House House
ISBN Verifier ISBN Verifier
Killer Sudoku Helper Killer Sudoku Helper
Kindergarten Garden Kindergarten Garden
Ledger Ledger
Lens Person Lens Person
List Ops List Ops
Luhn Luhn
Markdown Markdown
Matching Brackets Matching Brackets
Matrix Matrix
Meetup Meetup
Micro Blog Micro Blog
Minesweeper Minesweeper
Nth Prime Nth Prime
Nucleotide Count Nucleotide Count
OCR Numbers OCR Numbers
POV POV
PaaS I/O PaaS I/O
Palindrome Products Palindrome Products
Parallel Letter Frequency Parallel Letter Frequency
Pascal's Triangle Pascal's Triangle
Perfect Numbers Perfect Numbers
Phone Number Phone Number
Pig Latin Pig Latin
Poker Poker
Prime Factors Prime Factors
Proverb Proverb
Pythagorean Triplet Pythagorean Triplet
Queen Attack Queen Attack
REST API REST API
RNA Transcription RNA Transcription
Rail Fence Cipher Rail Fence Cipher
Rational Numbers Rational Numbers
React React
Rectangles Rectangles
Resistor Color Resistor Color
Resistor Color Duo Resistor Color Duo
Resistor Color Trio Resistor Color Trio
Reverse String Reverse String
Robot Name Robot Name
Rotational Cipher Rotational Cipher
Run-Length Encoding Run-Length Encoding
SGF Parsing SGF Parsing
Satellite Satellite
Say Say
Scale Generator Scale Generator
Scrabble Score Scrabble Score
Series Series
Simple Cipher Simple Cipher
Simple Linked List Simple Linked List
Spiral Matrix Spiral Matrix
Square Root Square Root
State of Tic-Tac-Toe State of Tic-Tac-Toe
Strain Strain
Sublist Sublist
Tournament Tournament
Transpose Transpose
Tree Building Tree Building
Triangle Triangle
Twelve Days Twelve Days
Variable Length Quantity Variable Length Quantity
Word Count Word Count
Word Search Word Search
Wordy Wordy
Zebra Puzzle Zebra Puzzle
Zipper Zipper