Kata Library: JavaScript Practice
Sign Up
Time to claim your honor
Training
Practice
Complete challenging
Kata
to earn honor and ranks. Re-train to hone technique
Freestyle Sparring
Take turns remixing and refactoring others code through
Kumite
Community
Leaderboards
Achieve honor and move up the global leaderboards
Chat
Join our
Discord
server and chat with your fellow code warriors
Discussions
View our
Github Discussions
board to discuss general Codewars topics
About
Docs
Learn about all of the different aspects of Codewars
Blog
Read the latest news from Codewars and the community
Log In
Sign Up
Library
Collections
Newest
Oldest
Popularity
Positive Feedback
Most Completed
Least Completed
Hardest
Easiest
Name
Relevance
Low Satisfaction
All
My Languages
Agda (Beta)
BF (Beta)
C
CFML (Beta)
Clojure
COBOL (Beta)
CoffeeScript
CommonLisp (Beta)
Coq
C++
Crystal
C#
D (Beta)
Dart
Elixir
Elm (Beta)
Erlang (Beta)
Factor (Beta)
Forth (Beta)
Fortran (Beta)
F#
Go
Groovy
Haskell
Haxe (Beta)
Idris (Beta)
Java
JavaScript
Julia (Beta)
Kotlin
λ Calculus (Beta)
Lean
Lua
NASM
Nim (Beta)
Objective-C (Beta)
OCaml (Beta)
Pascal (Beta)
Perl (Beta)
PHP
PowerShell (Beta)
Prolog (Beta)
PureScript (Beta)
Python
R (Beta)
Racket
Raku (Beta)
Reason (Beta)
RISC-V (Beta)
Ruby
Rust
Scala
Shell
Solidity (Beta)
SQL
Swift
TypeScript
VB (Beta)
Approved & Beta
Approved
Beta
All
Kata I have not trained on
Kata I have not completed
Kata I have completed
8 kyu
easiest
7 kyu
6 kyu
5 kyu
4 kyu
3 kyu
2 kyu
1 kyu
hardest
Algorithms
47
Arrays
45
Binary Trees
3
Compilers
1
Data Structures
28
Debugging
1
Esoteric Languages
2
Functional Programming
125
Fundamentals
74
Interpreters
2
Language Features
1
Lists
15
Logic
1
Mathematics
4
Metaprogramming
1
Monads
1
Parsing
1
Performance
1
Puzzles
5
Recursion
4
Refactoring
5
Regular Expressions
4
Restricted
1
Set Theory
1
Sets
1
Sorting
1
Streams
1
Strings
21
Trees
3
FEATURED TAGS
Cryptography
Data Science
Debugging
Games
Tutorials
125 Kata Found
5 kyu
Calculating with Functions
87,424
BattleRattle
1 Issue Reported
Functional Programming
7 kyu
Adding useful functional functionality to JavaScript arrays
4,098
r0ze
Functional Programming
Fundamentals
6 kyu
Coding Meetup #10 - Higher-Order Functions Series - Create usernames
3,509
PiotrBerebecki
Functional Programming
Data Structures
Arrays
Fundamentals
Algorithms
Strings
7 kyu
Homogenous arrays
4,517
lilsweetcaligula
Arrays
Fundamentals
Functional Programming
7 kyu
Coding Meetup #4 - Higher-Order Functions Series - Find the first Python developer
10,390
PiotrBerebecki
1 Issue Reported
Functional Programming
Data Structures
Arrays
Fundamentals
Algorithms
Strings
Regular Expressions
7 kyu
Coding Meetup #2 - Higher-Order Functions Series - Greet developers
12,856
PiotrBerebecki
Data Structures
Fundamentals
Algorithms
Strings
Regular Expressions
Arrays
Functional Programming
7 kyu
Coding Meetup #1 - Higher-Order Functions Series - Count the number of JavaScript developers coming from Europe
16,628
PiotrBerebecki
1 Issue Reported
Data Structures
Fundamentals
Algorithms
Strings
Regular Expressions
Arrays
Functional Programming
7 kyu
Sum of Odd Cubed Numbers
11,689
elliottmck
5 Issues Reported
Fundamentals
Functional Programming
Arrays
7 kyu
Coding Meetup #3 - Higher-Order Functions Series - Is Ruby coming?
11,138
PiotrBerebecki
1 Issue Reported
Data Structures
Fundamentals
Algorithms
Strings
Regular Expressions
Arrays
Functional Programming
7 kyu
Unpacking Arguments
13,463
user578387
1 Issue Reported
Functional Programming
Fundamentals
6 kyu
zipWith
7,292
JohanWiltink
Lists
Arrays
Functional Programming
Algorithms
6 kyu
Reducing by steps
4,534
g964
3 Issues Reported
Mathematics
Arrays
Functional Programming
Lists
Data Structures
1 kyu
Functional SQL
2,902
surtich
2 Issues Reported
Functional Programming
Algorithms
6 kyu
Once
6,204
osuushi
3 Issues Reported
Functional Programming
Fundamentals
5 kyu
Partition On
6,667
jcorbin@wunjo.org
1 Issue Reported
Functional Programming
Arrays
Algorithms
7 kyu
Functional Addition
18,797
amrdraz
Functional Programming
Fundamentals
6 kyu
Unary function chainer
7,263
tpatja
Functional Programming
Fundamentals
7 kyu
First-Class Function Factory
7,657
otajor
Fundamentals
Functional Programming
Arrays
7 kyu
Pair Zeros
2,370
Nianpeng
Algorithms
Arrays
Fundamentals
Functional Programming
7 kyu
Currying functions: multiply all elements in an array
16,268
limeyb7
1 Issue Reported
Functional Programming
Fundamentals
8 kyu
Dollars and Cents
25,966
kolohelios
1 Issue Reported
Functional Programming
Strings
Algorithms
7 kyu
Coding Meetup #17 - Higher-Order Functions Series - Sort by programming language
2,166
PiotrBerebecki
Functional Programming
Data Structures
Arrays
Fundamentals
Algorithms
Sorting
4 kyu
Functional streams
776
muesli4
2 Issues Reported
Streams
Functional Programming
Algorithms
6 kyu
A functional deck of cards....
881
thatrubylove
5 Issues Reported
Functional Programming
Fundamentals
2 kyu
Regular expression parser
1,172
phaul
15 Issues Reported
Parsing
Functional Programming
Algorithms
6 kyu
Fun with lists: map
1,708
janitormeir
Lists
Functional Programming
Fundamentals
6 kyu
The takeWhile Function
2,471
jgdodson
2 Issues Reported
Functional Programming
Arrays
Algorithms
Lists
Data Structures
7 kyu
The dropWhile Function
3,498
jgdodson
1 Issue Reported
Functional Programming
Arrays
Algorithms
8 kyu
The 'if' function
34,506
user578387
10 Issues Reported
Functional Programming
Fundamentals
7 kyu
Coding Meetup #5 - Higher-Order Functions Series - Prepare the count of languages
8,315
PiotrBerebecki
Functional Programming
Data Structures
Arrays
Fundamentals
Algorithms
Loading...
Confirm
Collect:
undefined
Loading collection data...