Regular Expressions 101

Save & Share

  • Regex Version: ver. 2
  • Update Regex
    ctrl+⇧+s
  • Save new Regex
    ctrl+s
  • Add to Community Library

Flavor

  • PCRE2 (PHP >=7.3)
  • PCRE (PHP <7.3)
  • ECMAScript (JavaScript)
  • Python
  • Golang
  • Java 8
  • .NET 7.0 (C#)
  • Rust
  • Regex Flavor Guide

Function

  • Match
  • Substitution
  • List
  • Unit Tests (1)

Tools

Sponsors
There are currently no sponsors. Become a sponsor today!
An explanation of your regex will be automatically generated as you type.
Detailed match information will be displayed here automatically.
  • All Tokens
  • Common Tokens
  • General Tokens
  • Anchors
  • Meta Sequences
  • Quantifiers
  • Group Constructs
  • Character Classes
  • Flags/Modifiers
  • Substitution
  • A single character of: a, b or c
    [abc]
  • A character except: a, b or c
    [^abc]
  • A character in the range: a-z
    [a-z]
  • A character not in the range: a-z
    [^a-z]
  • A character in the range: a-z or A-Z
    [a-zA-Z]
  • Any single character
    .
  • Alternate - match either a or b
    a|b
  • Any whitespace character
    \s
  • Any non-whitespace character
    \S
  • Any digit
    \d
  • Any non-digit
    \D
  • Any word character
    \w
  • Any non-word character
    \W
  • Non-capturing group
    (?:...)
  • Capturing group
    (...)
  • Zero or one of a
    a?
  • Zero or more of a
    a*
  • One or more of a
    a+
  • Exactly 3 of a
    a{3}
  • 3 or more of a
    a{3,}
  • Between 3 and 6 of a
    a{3,6}
  • Start of string
    ^
  • End of string
    $
  • A word boundary
    \b
  • Non-word boundary
    \B

Regular Expression
No Match

/
/
gm

Test String

Substitution

Processing...

Code Generator

Language

Generated Code

const regex = /(?<topro>\([^)]*?\bpro +)(?<afterpro>.*?\))|(?<withoutpro>\(.*?\))/gm; // Alternative syntax using RegExp constructor // const regex = new RegExp('(?<topro>\\([^)]*?\\bpro +)(?<afterpro>.*?\\))|(?<withoutpro>\\(.*?\\))', 'gm') const str = `4377631753733131 (pro alber con tr33) 886uhghsdfdsfh (pro cios tui tr32) rtyqrey 6y46457 6372576 (Flrt ghnap tsr) 537657QQRFytyvg (flipzz Reyhdf frfg33) 4377631753733131 (pro alber con tr33) (flipzz Reyhdf frfg33) (foo pro bar pro cios tui tr32) I would like all words after "pro" to be capitalized. If "pro" is not present, all words in the brackets must be lowercase, for have : 4377631753733131 (pro Alber Con Tr33) 886uhghsdfdsfh (pro Cios Tui Tr32) rtyqrey 6y46457 6372576 (flrt ghnap tsr) 537657QQRFytyvg (flipzz reyhdf frfg33)`; const subst = `${topro}\U${afterpro}\L${withoutpro}\E`; // The substituted value will be contained in the result variable const result = str.replace(regex, subst); console.log('Substitution result: ', result);

Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for JavaScript, please visit: https://developer.mozilla.org/en/docs/Web/JavaScript/Guide/Regular_Expressions