Regular Expressions 101

Save & Share

  • Regex Version: ver. 5
  • 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

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

/
/
gim

Test String

Substitution

Processing...

Code Generator

Language

Generated Code

package main import ( "regexp" "fmt" ) func main() { var re = regexp.MustCompile(`(?im)("(post\s*(office)?)?\s*box\s*[#-]?\s*(\d+)?"|"[\w\s]*?p(ost)?\s*[.-]?\s*o?\s*\.?\s*b?(ox)?\.?\s*(\d+)?"|"\s*number\s*\d+")`) var str = ` "Box 123", "Box-122", "Box122", "HC73 P.O. Box 217", "P O Box125", "P. O. Box", "P.O 123", "P.O. Box 123", "P.O. Box", "P.O.B 123", "P.O.B. 123", "P.O.B.", "POB 123", "POB", "POBOX123", "Po Box", "Post 123", "Post Box 123", "Post Office Box 123", "Post Office Box", "box #123", "box 122", "box 123", "number 123", "p box", "p-o box", "post office box" "The Postal Road", "Box Hill", "123 Some Street", "Controller's Office", "pollo St.", "123 box canyon rd", "777 Post Oak Blvd", "PSC 477 Box 396", "RR 1 Box 1020"` var substitution = "" 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/