Regular Expressions 101

Save & Manage Regex

  • Current Version: 1
  • Save & Share
  • Community Library

Flavor

  • PCRE2 (PHP)
  • ECMAScript (JavaScript)
  • Python
  • Golang
  • Java
  • .NET 7.0 (C#)
  • Rust
  • PCRE (Legacy)
  • Regex Flavor Guide

Function

  • Match
  • Substitution
  • List
  • Unit Tests
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
Processing...

Test String

Code Generator

Language

Generated Code

package main import ( "regexp" "fmt" ) func main() { var re = regexp.MustCompile(`(?i)((?<!\d|\.)([0-9]?[0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])(?!\d|\.) *[,;] *){2}(?<!\d|\.)([0-9]?[0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])(?!\d|\.)`) var str = `RGBA: (0-255) 204, 128, 128, 255 RGBA: (0-255) 4, 128, 128, 255 RGBA: (0-255) 204, 18, 928, 255 RGBA: (0-255) 304, 1, 18, 255 RGBA: (0-255) 204, 28, 128, 25, 25, 255, 152, 12 RGBA: (0-255) 204, 128, 8, 5 RGBA: (0-255) 204, 128, 128, 355 RGBA: (0-255) 204, 128, 128, 265 RGBA: (0-255) 204, 128, 128, 256 bonjour, 18, 928, 255 RGBA: (0-1) 0.8, 0.502, 0.502, 1 RGB: #cc8080 RGBA: #cc8080ff ARGB: #ffcc8080 CMYK: 0, 37, 37, 19 HSLA: 360, 43, 65, 1` for i, match := range re.FindAllString(str, -1) { fmt.Println(match, "found at index", i) } }

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 Golang, please visit: https://golang.org/pkg/regexp/