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Quick TrainerJavaScript String Methods
Learn what common JavaScript string methods do and recall them both ways.
Code29 items3 levelsDifficulty 2/5
Free · no signup · works on any device
Levels
Start easy — harder levels unlock as you improve, or jump ahead anytime.
1
Everyday
10 items
2
Common
11 items
3
Advanced
8 items
All 29 cards
length
number of characters
toUpperCase()
convert to uppercase
toLowerCase()
convert to lowercase
trim()
remove whitespace from both ends
includes()
check if substring exists
indexOf()
first index of substring
slice()
extract part of a string
split()
split string into an array
replace()
replace first match
charAt()
character at an index
concat()
join strings together
startsWith()
check if string starts with text
endsWith()
check if string ends with text
substring()
extract characters between two indexes
repeat()
repeat string a number of times
replaceAll()
replace all matches
padStart()
pad start to a target length
padEnd()
pad end to a target length
lastIndexOf()
last index of substring
trimStart()
remove leading whitespace
trimEnd()
remove trailing whitespace
charCodeAt()
UTF-16 code of character at index
codePointAt()
Unicode code point at index
localeCompare()
compare strings in sort order
normalize()
return Unicode normalized form
match()
match string against a regex
matchAll()
get all regex matches
search()
index of first regex match
at()
character at index (supports negative)
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