Regular Expressions 101

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2

Find 'console.' but not 'console.log'

ECMAScript (JavaScript)
no description available
Submitted by Jay Johnson - 10 years ago
1

Find UnCommented Console. Code

ECMAScript (JavaScript)
no description available
Submitted by Jay Johnson - 10 years ago
0

Splits jquery selector, 2nd part is selector of last element

ECMAScript (JavaScript)
no description available
Submitted by Uzair Farooq - 10 years ago
1

Singular or Plural

ECMAScript (JavaScript)
no description available
Submitted by Gavin Jackson - 10 years ago
2

US and Canada Regex

ECMAScript (JavaScript)
A zipcode regex for validation of both US and Canada
Submitted by Kyle M. - 10 years ago
-1

email

ECMAScript (JavaScript)
no description available
Submitted by anonymous - 10 years ago
-2

email

ECMAScript (JavaScript)
no description available
Submitted by anonymous - 10 years ago
0

adding space after (.) period and next word

ECMAScript (JavaScript)
Requirement was to check if there is space between . and next text and if not the then add space
Submitted by Prajkta - 10 years ago
2

US Postal Code

ECMAScript (JavaScript)
refactor
Submitted by jay johnson - 10 years ago
3

mm/dd/yyyy Date

ECMAScript (JavaScript)
no description available
Submitted by jay johnson - 10 years ago
0

Phone area code - prefix - number

ECMAScript (JavaScript)
no description available
Submitted by anonymous - 10 years ago
1

SSN

ECMAScript (JavaScript)
no description available
Submitted by jay johnson - 10 years ago
-2

non-negative integer

ECMAScript (JavaScript)
repeat ... refactor
Submitted by jay johnson - 10 years ago
1

non negative integers

ECMAScript (JavaScript)
no description available
Submitted by jay johnson - 10 years ago
14

us postal/zip

ECMAScript (JavaScript)
no description available
Submitted by jay johnson - 10 years ago
5

Accept url without www

ECMAScript (JavaScript)
no description available
Submitted by anonymous - 10 years ago
1

Matching an Email

ECMAScript (JavaScript)
no description available
Submitted by appsunited - 10 years ago
7

Split quotes and single words

ECMAScript (JavaScript)
Find " and ' quoted strings and "orphaned"/single words in a string
Submitted by LoveIsGrief - 10 years ago
1

Replace second (or further) html statement in a whole code

ECMAScript (JavaScript)
This regex replace the second tag content which has the prefix ":". If you want to replace the third, just increase the statement {1} to {2}, and so go on.
Submitted by Caio Oliveira - 10 years ago
1

regular expression to replace except text from html tags

ECMAScript (JavaScript)
expression to look for words in innerText & not in html tags as id or class or style name
Submitted by umarfarukh - 10 years ago
1...286287288289

JavaScript number literals

1

Regular Expression
ECMAScript (JavaScript)

/
^([+-]?(?:NaN|Infinity|0(?:[bB][01](?:_?[01]+)*|[oO]?[0-7](?:_?[0-7]+)*|[xX][0-9a-fA-F](?:_?[0-9a-fA-F]+)*)|(?:(?:0|0(?:[0-9](?:_?[0-9]+)*)?[89](?:[0-9](?:_?[0-9]+)*)?|[1-9](?:_?[0-9]+)*)(?:\.(?:[0-9](?:_?[0-9]+)*)?)?|\.[0-9](?:_?[0-9]+)*)(?:[eE][+-]?[0-9](?:_?[0-9]+)*)?)|-?(?:0(?:[bB][01](?:_?[01]+)*|[oO][0-7](?:_?[0-7]+)*|[xX][0-9a-fA-F](?:_?[0-9a-fA-F]+)*)?|[1-9](?:_?[0-9]+)*)n)$
/
gm
Open regex in editor

Description

Should match any valid JavaScript number literal incl. bigint.

See EDIT 4 in this StackOverflow answer by me for matching JS numbers.

open in regex101 editor - example matches and unit tests
Regulex - colored graph
Regexper - slightly smaller and less colored graph

  • +/- Infinity and NaN
  • _ as numerical separator between any two digits
  • Number
    • leading/trailing . (decimal point)
    • leading 0s
      • [!] may be interpreted as octal (see below)
    • prefix
      • 0b binary
        • no . or scientific notation
      • 0o octal
        • [!] also implicit with leading 0 and when all digits (before any .) are below 8
        • no . or scientific notation
      • 0x hexadecimal
        • no . or scientific notation
          • [!] the E in scientific notation will be part of the hexadecimal number
  • BigInt
    • explicit via suffix n
    • no leading 0s except after a 0o/0x/0b prefix
    • no +, ., or scientific notation

Note, Number() allows leading/trailing whitespace, but not _, and leading 0s are not an implicit octal prefix, (and ofc no BigInt suffix)

Submitted by MAZ01001 - 3 months ago (Last modified 7 days ago)