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
No Match

/
/
gm

Test String

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 = "^[A-Z0-9]+(?:-[A-Z0-9]+)?(?:,[A-Z0-9]+(?:-[A-Z0-9]+)?)*$"; final String string = "//Valid Values\n" + "D1\n" + "DF2,AB2\n" + "D1-2\n" + "A1, A2\n" + "D1 - 2\n" + "1 - FH15\n" + "1-R3\n" + "1,D2\n" + "1,H5,8,S4\n" + "1 , H5, 8, S4\n" + "1, D2, D6-8, 6-9\n" + "1,D2,D6-8,6-9,G2,8\n" + "1-D3,TT6-8\n" + "1-D3, TT6-8\n" + "1-3, VB8, 11-SD13, R15\n\n" + "//Invalid values\n" + "1*, 3\n" + ",1,F2\n" + "-1-TG3\n" + "12-D4,\n" + "D1-F2-\n" + "1- F2- 4\n" + "D10,/\n" + "1234s\n" + "F4-,8\n" + "4,-H5\n" + "D3-F-G7\n" + "D3 - F - G7\n" + "4 , - H5\n" + "1*,D\n" + "12 - D4"; 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