Regular Expressions 101

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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

/
/
gm

Test String

Code Generator

Generated Code

import java.util.regex.Matcher; import java.util.regex.Pattern; public class Example { public static void main(String[] args) { final String regex = "(?:\\b(?P<month>0?[1-9]|0?1[012])[\\/-](?P<day>0?[1-9]|[12][0-9]|3[01])[\\/-](?P<year>\\d{2,4})\\b)|(?:(?P<month1>0?[1-9]|1[012])[\\/](?P<year1>\\d{4})\\b)|(?:\\b(?P<month2>Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)[a-z]{0,6}[. \\/-]+(?P<day2>0?[1-9]|[12][0-9]|3[01])(?:th|st|nd)?[ ,\\/-]+(?P<year2>\\d{2,4})\\b)|(?:\\b(?P<day3>0?[1-9]|[12][0-9]|3[01])[ ,\\/-]+(?P<month3>Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)[a-z]{0,6}[,. \\/-]+(?P<year3>\\d{2,4})\\b)|(?:(?P<month4>Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)[a-z]{0,6}[,. \\/-]+(?P<year4>\\d{2,4})\\b)|(?:(?P<year5>[12]\\d{3})\\b)"; final String string = "\n" + "04/20/2009; 04/20/09; 4/20/09; 4/3/09\n" + "Mar-20-2009; Mar 20, 2009; March 20, 2009; Mar. 20, 2009; Mar 20 2009;\n" + "20 Mar 2009; 20 March 2009; 20 Mar. 2009; 20 March, 2009\n" + "Mar 20th, 2009; Mar 21st, 2009; Mar 22nd, 2009\n" + "Feb 2009; Sep 2009; Oct 2010\n" + "6/2008; 12/2009\n" + "2009; 2010\n" + "011/14/83\n" + "16/22 \n" + "9/22\n" + "r1978\n" + "n4/2004\n" + "e12/2007\n" + "08-810-7787\n" + "pOct 2015\n" + "Janaury 1993\n" + "Married to husband for 50+ years\n\n" + "0 03/25/93 Total time of visit (in minutes):\\n\n" + "1 6/18/85 Primary Care Doctor:\\n\n" + "2 sshe plans to move as of 7/8/71 In-Home Servic...\n" + "3 7 on 9/27/75 Audit C Score Current:\\n\n" + "4 2/6/96 sleep studyPain Treatment Pain Level (N...\n" + "5 .Per 7/06/79 Movement D/O note:\\n\n" + "6 4, 5/18/78 Patient's thoughts about current su...\n" + "7 10/24/89 CPT Code: 90801 - Psychiatric Diagnos...\n" + "8 3/7/86 SOS-10 Total Score:\\n\n" + "9 (4/10/71)Score-1Audit C Score Current:\\n\n" + "10 (5/11/85) Crt-1.96, BUN-26; AST/ALT-16/22; WBC...\n" + "11 4/09/75 SOS-10 Total Score:\\n\n" + "12 8/01/98 Communication with referring physician...\n" + "13 1/26/72 Communication with referring physician...\n" + "14 5/24/1990 CPT Code: 90792: With medical servic...\n" + "15 1/25/2011 CPT Code: 90792: With medical servic...\n" + "16 4/12/82 Total time of visit (in minutes):\\n\n" + "17 1; 10/13/1976 Audit C Score, Highest/Date:\\n\n" + "18 4, 4/24/98 Relevant Drug History:\\n\n" + "19 ) 59 yo unemployed w referred by Urgent Care f...\n" + "20 7/21/98 Total time of visit (in minutes):\\n\n" + "21 10/21/79 SOS-10 Total Score:\\n\n" + "22 3/03/90 CPT Code: 90792: With medical services\\n\n" + "23 2/11/76 CPT Code: 90792: With medical services\\n\n" + "24 07/25/1984 CPT Code: 90791: No medical services\\n\n" + "25 4-13-82 Other Child Mental Health Outcomes Sca...\n" + "26 9/22/89 CPT Code: 90792: With medical services\\n\n" + "27 9/02/76 CPT Code: 90791: No medical services\\n\n" + "28 9/12/71 [report_end]\\n\n" + "29 10/24/86 Communication with referring physicia..."; final Pattern pattern = Pattern.compile(regex, Pattern.MULTILINE); final Matcher matcher = pattern.matcher(string); while (matcher.find()) { System.out.println("Full match: " + matcher.group(0)); for (int i = 1; i <= matcher.groupCount(); i++) { System.out.println("Group " + i + ": " + matcher.group(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 Java, please visit: https://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html