Regular Expressions 101

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  • All Tokens
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  • 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
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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 = "(?:^|(?<=\\|))[^|]*\\bpresident\\b[^|]*(?=\\||$)"; final String string = "{{Redirect|Harvard}} {{pp-move-indef}} {{Use mdy dates|date=August \n" + "2014}} {{pp-semi-blp|small=yes}}{{Infobox university |name = Harvard \n" + "University |image_name = Harvard Wreath Logo 1.svg |image_size = |caption \n" + "= [[Seal (emblem)|Seal]] of Harvard University |latin_name = Universitas \n" + "Harvardiana |motto = ''Veritas''Harvard's ''Veritas'' appears on the \n" + "university's arms; [[Heraldry|heraldically]] speaking, however, a 'motto' \n" + "is a word or phrase displayed on a scroll in conjunction with a shield of \n" + "arms. [https://books.google.com/books?\n" + "id=zkQWZaZqZfUC&pg=PA330&lpg=PA330#v=onepage&q&f=false Since 1692] \n" + "University [[seal (device)|seals]] have borne ''Christo et Ecclesiae'' \n" + "(for Christ and the Church) in this manner, arguably making that phrase \n" + "the university's motto in a heraldic sense. This legend is otherwise not \n" + "in general use today. |established = 1636An appropriation of £400 toward \n" + "a \"school or college\" was voted on October 28, 1636 (OS), at a meeting \n" + "which convened on September 8 and was adjourned to October 28. Some \n" + "sources consider October 28, 1636 (OS) (November 7, 1636 NS) to be the \n" + "date of founding. Harvard's 1936 tercentenary celebration treated \n" + "September 18 as the founding date, though 1836 bicentennial was \n" + "celebrated on September 8, 1836. Sources: meeting dates, {{cite \n" + "book|first=Josiah|last=Quincy|title=History of Harvard University \n" + "|year=1860 |publisher=Crosby, Nichols, Lee and Co.|location=117 \n" + "Washington Street, Boston}}, [https://books.google.com/books?\n" + "vid=OCLC11636583&id=KynqxH_4lGUC&pg=RA1-PA586&lpg=RA1-PA586 p. 586], \"At \n" + "a Court holden September 8th, 1636 and continued by adjournment to the \n" + "28th of the 8th month (October, 1636)... the Court agreed to give £400 \n" + "towards a School or College, whereof £200 to be paid next year....\" \n" + "Tercentenary dates: {{cite \n" + "news|url=http://www.time.com/time/\n" + "magazine/printout/0,8816,756722,00.html|date=September 28, \n" + "1936|accessdate=September 8, 2006|work=Time|title=Cambridge Birthday}}: \n" + "\"Harvard claims birth on the day the Massachusetts Great and General \n" + "Court convened to authorize its founding. This was Sept. 8, 1637 under \n" + "the Julian calendar. Allowing for the ten-day advance of the Gregorian \n" + "calendar, Tercentenary officials arrived at Sept. 18 as the date for the \n" + "third and last big Day of the celebration;\" \"on Oct. 28, 1636 ... £400 \n" + "for that 'school or college' [was voted by] the Great and General Court \n" + "of the [[Massachusetts Bay Colony]].\" Bicentennial date: {{cite web \n" + "|url=http://www.news.harvard.edu/gazette/2003/10.02/02-\n" + "history.html|publisher=Harvard University|title=Harvard Gazette: This \n" + "Month in Harvard History|date=September 2, 2003 |accessdate=September 15, \n" + "2006|author=Marvin Hightower}}, \"Sept. 8, 1836 - Some 1,100 to 1,300 \n" + "alumni flock to Harvard's Bicentennial, at which a professional choir \n" + "premieres \"Fair Harvard.\" ... guest speaker Josiah Quincy Jr., Class of \n" + "1821, makes a motion, unanimously adopted, 'that this assembly of the \n" + "Alumni be adjourned to meet at this place on September 8, 1936.'\" \n" + "Tercentary opening of Quincy's sealed package: ''The New York Times,'' \n" + "September 9, 1936, p. 24, \"Package Sealed in 1836 Opened at Harvard. It \n" + "Held Letters Written at Bicentenary\": \"September 8th, 1936: As the first \n" + "formal function in the celebration of Harvard's tercentenary, the Harvard \n" + "Alumni Association witnessed the opening by President Conant of the \n" + "'mysterious' package sealed by President Josiah Quincy at the Harvard \n" + "bicentennial in 1836.\" |mottoeng = Truth |type = [[Private \n" + "university|Private]] – [[Research]] |calendar = Semester |endowment = \n" + "$36.4 billion{{As of|2014|06|30}}. {{cite web | title = Harvard Endowment \n" + "Earns 15.4% Return for Fiscal 2014| work = The Wall Street Journal | url \n" + "= http://online.wsj.com/articles/harvard-endowment-earns-15-4-return-for-\n" + "fiscal-2014-1411506002 | accessdate=10 October 2014}} |president = [[Drew \n" + "Gilpin Faust]] |students = 21,000{{As of|2014|09|01}}. {{cite web | title \n" + "= Harvard at a Glance| work = Harvard University | url = \n" + "http://www.harvard.edu/harvard-glance | accessdate=27 November 2014}} \n" + "|undergrad = 6,700 |postgrad = 14,500 |staff = |faculty = 4,671{{Cite \n" + "book|last=Office of Institutional Research.|title=Harvard University Fact \n" + "Book|year=2009|chapter=Faculty|url=http:// \n" + "www.provost.harvard.edu/institutional_research/Provost_-_09_18-\n" + "19facuni.pdf}} (\"Unduplicated, Paid Instructional Faculty Count: 2,107. \n" + "Unduplicated instructional faculty count is the most appropriate count \n" + "for general reporting purposes.\") |city = [[Cambridge, \n" + "Massachusetts|Cambridge]] |state = [[Massachusetts]] |country = United \n" + "States |campus = [[Urban area|Urban]]{{Convert|210|acre|ha}} (Main \n" + "campus){{Convert|21|acre|ha}} (Medical campus)\n" + "{{Convert|360|acre|ha}} (Allston campus)\n" + "{{Convert|4500|acre|ha}} (other holdings) |sports = 42 varsity teams \n" + "|athletics = [[National Collegiate Athletic Association|NCAA]] [[Division \n" + "I (NCAA)|Division I]] – [[Ivy League]] |nickname = [[Harvard Crimson]] \n" + "|colors = {{color box|#A41034}} [[Crimson]]{{cite web|title=Color - \n" + "Identity Guidelines - Harvard Business \n" + "School|url=http://www.hbs.edu/marketing/color.html|publisher=Harvard \n" + "Business School|accessdate=26 September 2014}} |free_label = Student \n" + "newspaper |free = ''[[The Harvard Crimson]]'' |affiliations = [[National \n" + "Association of Independent Colleges and Universities|NAICU]]\n" + "[[Association of Independent Colleges and Universities in \n" + "Massachusetts|AICUM]][[Association of American Universities|AAU]]\n" + "[[Universities Research Association|URA]] |website = \n" + "{{URL|http://www.harvard.edu/|Harvard.edu}} |logo = [[File:Harvard \n" + "University logo.PNG|Harvard University logo (with its coat of arms)]] \n" + "|publictransit = [[Harvard (MBTA station)]] }} '''Harvard University''' \n" + "is a [[Private university|private]] [[Ivy League]] [[Doctoral \n" + "university|research university]] in [[Cambridge, \n" + "Massachusetts|Cambridge]], [[Massachusetts]], established in 1636. Its \n" + "history, influence and wealth have made it one of the most prestigious \n" + "universities in the world.{{cite book|title=Making Harvard Modern: The \n" + "Rise of America's \n" + "University|last1=Keller|first1=Morton|last2=Keller\n" + "|first2=Phyllis|publisher=Oxford University Press|isbn=0-19-514457-\n" + "0|quote=Harvard's professional schools... won world prestige of a sort \n" + "rarely seen among social institutions. (...) Harvard's age, wealth, \n" + "quality, and prestige may well shield it from any conceivable \n" + "vicissitudes.|year=2001|pages=463–481}}{{Cite book|title=How Harvard \n" + "Rules: Reason in the Service of Empire|quote=... [Harvard's] tremendous \n" + "institutional power and prestige (...) Within the nation's (arguably) \n" + "most prestigious institution of higher learning ...|chapter=Sexual \n" + "Shakedown|pages=326–336|year=1989|publisher=South End Press|isbn=0-\n" + "89608-284-9|editor1-first=John|last=Spaulding|first=Christina|editor-\n" + "last=Trumpbour}}{{cite web|url=http://www.bloomberg.com/news/2011-03-\n" + "10/harvard-mit-ranked-most-prestigious-universities-study-\n" + "reports.html|title=Harvard, MIT Ranked Most Prestigious Universities, \n" + "Study Reports|author=David Altaner|publisher=Bloomberg|date=March 9, \n" + "2011|accessdate=March 1, 2012}}{{cite book|title=Collier's \n" + "Encyclopedia|publisher=Macmillan Educational Co.|year=1986|quote=Harvard \n" + "University, one of the world's most prestigious institutions of higher \n" + "learning, was founded in Massachusetts in 1636.}}{{cite \n" + "web|last=Newport|first=Frank|title=Harvard Number One University in Eyes \n" + "of Public Stanford and Yale in second \n" + "place|url=http://www.gallup.com/poll/9109/harvard-number-one-university-\n" + "eyes-public.aspx|publisher=Gallup}} Established originally by the \n" + "[[Massachusetts General Court|Massachusetts legislature]] and soon \n" + "thereafter named for [[John Harvard (clergyman)|John Harvard]] (its first \n" + "benefactor), Harvard is the [[Colonial Colleges|United States' oldest \n" + "institution of higher learning]],{{cite book|first1=Frederick \n" + "|last1=Rudolph|title=The American College and \n" + "University|year=1961|page=3|isbn=0-8203-1285-1|publisher=University of \n" + "Georgia Press}} and the [[Harvard Corporation]] (formally, the \n" + "''President and Fellows of Harvard College'')"; final Pattern pattern = Pattern.compile(regex); 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