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

/
/
gm

Test String

Substitution

Processing...

Code Generator

Language

Generated Code

package main import ( "regexp" "fmt" ) func main() { var re = regexp.MustCompile(`(?m)"amount":"[\$]?([0-9]{1,3}),([0-9]{1,3})"`) var str = `[{"team":"Green Bay Packers","active":"1","year_started":"2018","end_year":"2022","amount":"$2,578,408","amount_guaranteed":"$118,408"}] [{"team":"San Diego Padres","active":"0","year_started":"2020","end_year":"2020","amount":"563,500","amount_guaranteed":""},{"team":"San Diego Padres","active":"0","year_started":"2019","end_year":"2019","amount":"555,000","amount_guaranteed":""}] [{"team":"Washington Wizards","active":"1","year_started":"2019","end_year":"2021","amount":"$12,000,000","amount_guaranteed":"$12,000,000"},{"team":"Orlando Magic","active":"0","year_started":"2011","end_year":"2011","amount":"522,472","amount_guaranteed":""},{"team":"Orlando Magic","active":"0","year_started":"2012","end_year":"2013","amount":"2,854,389","amount_guaranteed":""},{"team":"Oklahoma City Thunder","active":"0","year_started":"2014","end_year":"2014","amount":"923,373","amount_guaranteed":""},{"team":"Houston Rockets","active":"0","year_started":"2014","end_year":"2014","amount":"981,084","amount_guaranteed":""},{"team":"Washington Wizards","active":"0","year_started":"2015","end_year":"2015","amount":"1,100,602","amount_guaranteed":""},{"team":"Detroit Pistons","active":"0","year_started":"2016","end_year":"2018","amount":"18,000,000","amount_guaranteed":""}]` var substitution = ""amount":"$1$2"," fmt.Println(re.ReplaceAllString(str, substitution)) }

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/