Regular Expressions 101

Save & Share

  • Regex Version: ver. 2
  • 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

r"
"
gm

Test String

Substitution

Processing...

Code Generator

Language

Generated Code

import java.util.regex.Matcher; import java.util.regex.Pattern; public class Example { public static void main(String[] args) { final String regex = "\\s*\\d+\\s*(?:units?|times?(?:\\s+(?:a|per)\\s+|\\s*/\\s*)(?:d(?:ay)?|w(?:ee)?k|month|y(?:ea)?r?))"; final String string = "inJECTable 1234 Eprex DOSE 4000 units on NONd\n" + "department 6789 DOSE 8000 units on DIALYSIS days - IV Interm',\n" + "inJECTable 4321 Eprex DOSE - 3 times/wk on NONdialysis day',\n" + "insulin MixTARD 30/70 - inJECTable 46 units',\n" + "insulin ISOPHANE -- InsulaTARD Vial - inJECTable 56 units SC SubCutaneous',\n" + "1-alfacalcidol DOSE 1 mcg - 3 times a week - IV Intermittent',\n" + "jevity liquid - FEEDS PO Jevity - 237 mL - 1 times per day',\n" + "1-alfacalcidol DOSE 1 mcg - 3 times per week - IV Intermittent',\n" + "1-supported DOSE 1 mcg - 1 time/day - IV Intermittent',\n" + "1-testpackage DOSE 1 mcg - 1 time a day - IV Intermittent\n\n" + "///3 times a day, 3 time/wk, 3 times per day, 3 times a month, 3 times/month"; final String subst = ""; final Pattern pattern = Pattern.compile(regex, Pattern.MULTILINE); final Matcher matcher = pattern.matcher(string); // The substituted value will be contained in the result variable final String result = matcher.replaceAll(subst); System.out.println("Substitution result: " + 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 Java, please visit: https://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html