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

/
/
g

Test String

Code Generator

Language

Generated Code

import Foundation let pattern = #"(?P<core1>(?i)[A-Z0-9]+)[\s]?((?i)out of|of|\/)[\s]?(?P<core2>(?i)[A-Z0-9]+)[\s]?(?:(?i)core[s]?|needle core[s]?)"# let regex = try! NSRegularExpression(pattern: pattern) let testString = ##""" ajnxaslndsa;ndaJDASDNsadnKDNadk;NADK'nadkAnaskdmaskdnajfbajfnakdnaj;knasjnakdna;jkdna;nda;dna;kdnas;dkns so as sadasldka aldaskl . asdas asd 5,400 cgy 40.00 cgy 4 cgy gleason score 6/10(4+3), = 7 ) 1.1- 0.6,df 2,4-3,6 asdf 4+5+6 gleason's pattern: 2+3, 5 gleason score = 5(2+3) score 1+2, (score 7) gleason Dec 2011-23 jan 500,000.012 cgy sdfsfsodm sdfsd f sdfsd afdas. s adasas dasd as asdasdaskd askdm askdmas'ljdnas;das.ndaskjndajkndWJDNAksz (?P<core1>(?i)[A-Z0-9]+)[\s]?((?i)out of|of|\/)[\s]?(?P<core2>(?i)[A-Z0-9]+)[\s]?(?:(?i)core[s]?|needle core[s]?) (?P<core1>(?i)[A-Z0-9]+)[\s]?((?i)core[s]? out of)[\s]?(?P<core2>(?i)[A-Z0-9]+) (?:(?i)involving)[\s]?(?P<core1>(?i)[A-Z0-9]+)[\s]?(?:(?i)core[s]?|needle core[s]?) 1 of 3 core one of three cores involving 1/2 cores involving five of six cores two of the cores one of multiple cores 1 of multiple cores two of 4 cores 5 of six cores (1/8 needle cores) (3/7 cores) one out of six cores two cores out of two 1 core out of 2 involving 1 core involving two cores gleason score 9, 4+5=9/10, PSA = 27.60, 8 specimens {0,1SDf00} 10% 20% (?<=(?i)gleason)[\w\s\p{P}\=]*[^0-9\.\+]*\s*\K(\d)\s*\+\s*(\d)(?=\D) (?<=(?i)gleason)[\w\s\p{P}\=]*[^0-9\.\+]*\s*\K(\d)\s*\+\s*(\d)(?=\D) (?<=(?i)gleason)[\w\s\p{P}\=]*[^0-9\.\-]*\s*\K(\d)\s*\-\s*(\d)(?=\D\-) (?<=(?i)gleason)[\w\s\p{P}\=]*[^0-9\.\,\#]*\s*\K(\d)\s*\,\s*(\d)(?=\D) [\w\s\p{P}\=]*[^0-9\.\+]*\s*\K(\d)\s*\+\s*(\d)(?=\D) [\w\s\p{P}\=]*[^0-9\.\-]*\s*\K(\d)\s*\+\s*(\d)(?=\D\-) (?<=[\\s])\\s*|^\\s+|\\s+$ """## let stringRange = NSRange(location: 0, length: testString.utf16.count) let matches = regex.matches(in: testString, range: stringRange) var result: [[String]] = [] for match in matches { var groups: [String] = [] for rangeIndex in 1 ..< match.numberOfRanges { let nsRange = match.range(at: rangeIndex) guard !NSEqualRanges(nsRange, NSMakeRange(NSNotFound, 0)) else { continue } let string = (testString as NSString).substring(with: nsRange) groups.append(string) } if !groups.isEmpty { result.append(groups) } } print(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 Swift 5.2, please visit: https://developer.apple.com/documentation/foundation/nsregularexpression