Regular Expressions 101

Save & Share

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

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

r"
"
g

Test String

Code Generator

Language

Generated Code

package main import ( "regexp" "fmt" ) func main() { var re = regexp.MustCompile(`([A-Z0-9-_]+).txt:\s?\s?([A-Z0-9-_:]+)\s+(\d+:\d+)|([A-Z0-9-_]+).txt:\s+(\w{6})\s+(\d+:\d+)`) var str = `RTARSPO0302.txt:MVNO_AMERICANET 26615:20891087 RTARSPO0302.txt: import 26615:30150 IPV4 Unicast RTARSPO0302.txt: import 26615:30200 IPV4 Unicast RTARSPO0302.txt:RAN_SHARING_OI 26615:20302087 RTARSPO0302.txt: import 26615:30200 IPV4 Unicast RTARSPO0302.txt: import 26615:30206 IPV4 Unicast RTARSPO0302.txt: import 26615:30301 IPV4 Unicast RTARSPO0302.txt: import 26615:30320 IPV4 Unicast RTARSPO0302.txt: export 26615:30301 IPV4 Unicast RTARSPO0302.txt: export 26615:303027 IPV4 Unicast RTARSPO0302.txt:TIMGPRS 26615:20203087 RTARSPO0302.txt: import 26615:30200 IPV4 Unicast RTARSPO0302.txt: import 26615:30301 IPV4 Unicast RTARSPO0302.txt: export 26615:30200 IPV4 Unicast RTARTSA0101.txt:DCN 26615:20705093 RTARTSA0101.txt: import 26615:30700 IPV4 Unicast RTARTSA0101.txt: export 26615:30700 IPV4 Unicast RTARTSA0101.txt:RAN_SHARING_OI 26615:20301093 RTARTSA0101.txt: import 26615:30301 IPV4 Unicast RTARTSA0101.txt: export 26615:30301 IPV4 Unicast R` 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/