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
ASCII Art
1
Algorithms
91
Angular
1
Arrays
33
Binary
3
Bits
1
Ciphers
2
Cryptography
2
Data Science
1
Data Structures
11
Date Time
5
Debugging
5
Design Patterns
1
Esoteric Languages
1
Filtering
2
Functional Programming
4
Fundamentals
217
Games
11
Interpreters
1
Language Features
2
Lists
1
Logic
4
Mathematics
6
Matrix
1
MongoDB
1
Networks
1
Number Theory
1
Object-oriented Programming
4
Parsing
16
Performance
1
Puzzles
19
Recursion
1
Regular Expressions
322
Restricted
2
Security
2
Sorting
1
Stacks
2
State Machines
1
Streams
1
Strings
173
Trees
1
Tutorials
7
FEATURED TAGS
Cryptography
Data Science
Debugging
Games
Tutorials
322 Kata Found
5 kyu
Not very secure
50,936
mayrsascha
6 Issues Reported
Regular Expressions
Strings
7 kyu
Exclamation marks series #5: Remove all exclamation marks from the end of words
4,646
myjinxin2015
Strings
Regular Expressions
Fundamentals
6 kyu
MAC Address : Regexp
267
osofem
Regular Expressions
Fundamentals
7 kyu
UVB-76 Message Validator
1,264
Drymonade
Algorithms
Strings
Regular Expressions
7 kyu
Digits explosion
18,746
angellaa
Strings
Regular Expressions
Fundamentals
6 kyu
Simple Simple Simple String Expansion
3,923
alansun
1 Issue Reported
Strings
Regular Expressions
Fundamentals
7 kyu
Russian postal code checker
3,140
dreadknight2008
1 Issue Reported
Regular Expressions
Strings
Fundamentals
4 kyu
Simplifying multilinear polynomials
5,133
SleepingCode
2 Issues Reported
Mathematics
Strings
Regular Expressions
Parsing
Fundamentals
4 kyu
Regular expression for binary numbers divisible by 5
2,310
aswitalski
Binary
Algorithms
Regular Expressions
5 kyu
Convert all the cases!
1,664
AJFarmar
1 Issue Reported
Strings
Regular Expressions
Algorithms
6 kyu
The Vowel Code
22,705
yaphi1
Arrays
Strings
Regular Expressions
Fundamentals
7 kyu
Check whether a number is valid in a given numeral system
1,225
SummerTheCoder
Algorithms
Logic
Regular Expressions
5 kyu
Advanced Pig Latin
1,219
davidbrear
Regular Expressions
Fundamentals
6 kyu
FIRE and FURY
1,554
dinglemouse
1 Issue Reported
Regular Expressions
Strings
Algorithms
7 kyu
Coding Meetup #4 - Higher-Order Functions Series - Find the first Python developer
10,401
PiotrBerebecki
1 Issue Reported
Functional Programming
Data Structures
Arrays
Fundamentals
Algorithms
Strings
Regular Expressions
6 kyu
Pirate treasure chest codes
343
roseinapuddle
1 Issue Reported
Strings
Regular Expressions
Puzzles
6 kyu
Coordinates Validator
7,145
louy
7 Issues Reported
Regular Expressions
Algorithms
6 kyu
IP Validation
44,605
wink
4 Issues Reported
Regular Expressions
Algorithms
7 kyu
Coding Meetup #2 - Higher-Order Functions Series - Greet developers
12,865
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
16,647
PiotrBerebecki
1 Issue Reported
Data Structures
Fundamentals
Algorithms
Strings
Regular Expressions
Arrays
Functional Programming
6 kyu
Simple Sentences
3,989
fizis
3 Issues Reported
Strings
Regular Expressions
Fundamentals
4 kyu
Breadcrumb Generator
4,858
GiacomoSorbi
Parsing
Regular Expressions
Algorithms
1 kyu
Full Metal Chemist #2: parse me...
136
Blind4Basics
1 Issue Reported
Regular Expressions
Puzzles
6 kyu
Valid Phone Number
21,449
xDranik
3 Issues Reported
Regular Expressions
Algorithms
6 kyu
Split Strings
170,189
jhoffner
Regular Expressions
Strings
Algorithms
5 kyu
ISBN-10 Validation
11,714
nklein
4 Issues Reported
Regular Expressions
Algorithms
7 kyu
Help Mr. E
998
methree
1 Issue Reported
Strings
Fundamentals
Regular Expressions
5 kyu
Return substring instance count - 2
3,234
ineiti
2 Issues Reported
Strings
Regular Expressions
Algorithms
5 kyu
Alphabet wars - nuclear strike
1,773
dcieslak
Strings
Regular Expressions
Fundamentals
7 kyu
Password validator
8,437
tdowek1
1 Issue Reported
Fundamentals
Regular Expressions
Algorithms
Loading...
Confirm
Collect:
undefined
Loading collection data...