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 = "(?<=[\\.,;\\s\\t\\n])[a-z0-9\\-]{2,}(?=[\\.,;\\s\\t\\n])"; final String string = " -a- -a-ll- [Enter KING HENRY, LORD JOHN OF , -,the;, LANCASTER , , the EARL\n" + "!and =all =12 ,123-,;, -qw !all a-a -doof I -i ,9ab+\n" + "xxx xx x !all ?nicht !and -doof -12 -aa\n" + " of WESTMORELAND, SIR WALTER BLUNT, and others]\n" + "12 d12a ; a1 d1a, ! ,aaaaa aaa ,aa1 .1a , ; !.a12\n" + "KING HENRY IV So !shaken as we, the are, so wan with care,\n" + " Find we a time; for frighted peace to pant,\n" + " And breathe short-winded accents of new broils\n" + " To be commenced in strands afar remote.\n" + " No more the thirsty entrance of this soil\n" + " Shall 12 daub her 1l1ips with her own children's blood;\n" + " Nor more shall trenching war channel her fields,\n" + " Nor bruise her flowerets with the armed hoofs\n" + " Of hostile paces: those opposed eyes,\n" + " Which, like the meteors of a troubled heaven,\n" + " All of one nature, of one substance bred,\n" + " Did lately meet in the intestine shock\n" + " And furious close of civil butchery\n" + " Shall now, in mutual well-beseeming ranks,\n" + " March all one way and be no more opposed\n" + " Against acquaintance, kindred and allies:\n" + " The edge of war, like an ill-sheathed knife,\n" + " No more shall cut his master. Therefore, friends,\n" + " As far as to the sepulchre of Christ,\n" + " Whose soldier now, under whose blessed cross\n" + " We are impressed and engaged to fight,\n" + " Forthwith a power of English shall we levy;\n" + " Whose arms were moulded in their mothers' womb\n" + " To chase these pagans in those holy fields\n" + " Over whose acres walk'd those blessed feet\n" + " Which fourteen hundred years ago were nail'd\n" + " For our advantage on the bitter cross.\n" + " But this our purpose now is twelve month old,\n" + " And bootless 'tis to tell you we will go:\n" + " Therefore we meet not now. Then let me hear\n" + " of you, my gentle cousin Westmoreland,\n" + " What yesternight our council did decree\n" + " In forwarding this dear expedience.\n\n" + "WESTMORELAND my liege, this haste was hot in question,\n"; 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