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

/
/
g

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-zA-Z ]+),"; final String string = "California\n\n" + "Alameda, CA\n" + "Albany, CA\n" + "Altadena, CA\n" + "Alviso, CA\n" + "Atherton, CA\n" + "Belmont, CA\n" + "Berkeley, CA\n" + "Beverly Hills, CA\n" + "Burbank, CA\n" + "Burlingame, CA\n" + "Campbell, CA\n" + "Culver City, CA\n" + "Cupertino, CA\n" + "El Cerrito, CA\n" + "Emeryville, CA\n" + "Encino, CA\n" + "Glendale, CA\n" + "La Canada Flintridge, CA\n" + "Los Altos, CA\n" + " \n" + "Los Angeles, CA\n" + "Los Gatos, CA\n" + "Marina Del Rey, CA\n" + "Menlo Park, CA\n" + "Millbrae, CA\n" + "Mountain View, CA\n" + "North Hollywood, CA\n" + "Oakland, CA\n" + "Pacific Palisades, CA\n" + "Palo Alto, CA\n" + "Pasadena, CA\n" + "Playa Del Rey, CA\n" + "Portola Valley, CA\n" + "Redwood City, CA\n" + "Reseda, CA\n" + "San Bruno, CA\n" + "San Carlos, CA\n" + "San Francisco, CA\n" + "San Jose, CA\n" + " \n" + "San Leandro, CA\n" + "San Marino, CA\n" + "San Mateo, CA\n" + "Santa Clara, CA\n" + "Santa Monica, CA\n" + "Saratoga, CA\n" + "Sherman Oaks, CA\n" + "South Pasadena, CA\n" + "South San Francisco, CA\n" + "Stanford, CA\n" + "Studio City, CA\n" + "Sunnyvale, CA\n" + "Tarzana, CA\n" + "Valley Village, CA\n" + "Van Nuys, CA\n" + "Venice, CA\n" + "West Hollywood, CA\n" + "Colorado\n\n" + "Boulder, CO\n" + "Denver, CO\n" + " \n" + "Englewood, CO\n" + "Lafayette, CO\n" + " \n" + "Louisville, CO\n" + "Connecticut\n\n" + "Canaan, CT\n" + "East Canaan, CT\n" + "Falls Village, CT\n" + " \n" + "Lakeville, CT\n" + "Norfolk, CT\n" + "Salisbury, CT\n" + " \n" + "Sharon, CT\n" + "Stamford, CT\n" + "West Cornwall, CT\n" + "District of Columbia\n\n" + "Washington, DC\n" + "Florida\n\n" + "Key Biscayne, FL\n" + "Miami Beach, FL\n" + " \n" + "Miami, FL\n" + "North Miami Beach, FL\n" + "Georgia\n\n" + "Alpharetta, GA\n" + "Atlanta, GA\n" + "Avondale Estates, GA\n" + " \n" + "Decatur, GA\n" + "Marietta, GA\n" + "Roswell, GA\n" + " \n" + "Scottdale, GA\n" + "Smyrna, GA\n" + "Illinois\n\n" + "Aurora, IL\n" + "Buffalo Grove, IL\n" + "Chicago, IL\n" + "Clarendon Hills, IL\n" + "Deerfield, IL\n" + "Downers Grove, IL\n" + "Elmhurst, IL\n" + "Evanston, IL\n" + "Fort Sheridan, IL\n" + "Glencoe, IL\n" + "Glenview Nas, IL\n" + "Glenview, IL\n" + "Grayslake, IL\n" + " \n" + "Highland Park, IL\n" + "Highwood, IL\n" + "Hinsdale, IL\n" + "Kenilworth, IL\n" + "Lake Bluff, IL\n" + "Lake Forest, IL\n" + "Lake Zurich, IL\n" + "Libertyville, IL\n" + "Lincolnshire, IL\n" + "Lincolnwood, IL\n" + "Lisle, IL\n" + "Mundelein, IL\n" + "Naperville, IL\n" + " \n" + "Northbrook, IL\n" + "Oak Brook, IL\n" + "Prospect Heights, IL\n" + "Skokie, IL\n" + "Vernon Hills, IL\n" + "Villa Park, IL\n" + "Warrenville, IL\n" + "Westmont, IL\n" + "Wheeling, IL\n" + "Wilmette, IL\n" + "Winnetka, IL\n" + "Indiana\n\n" + "Carmel, IN\n" + " \n" + "Fishers, IN\n" + " \n" + "Indianapolis, IN\n" + "Maryland\n\n" + "Bethesda, MD\n" + "Cabin John, MD\n" + "Chevy Chase, MD\n" + "Gaithersburg, MD\n" + " \n" + "Garrett Park, MD\n" + "Kensington, MD\n" + "Potomac, MD\n" + "Rockville, MD\n" + " \n" + "Silver Spring, MD\n" + "Takoma Park, MD\n" + "Massachusetts\n\n" + "Allston, MA\n" + "Arlington, MA\n" + "Ashley Falls, MA\n" + "Auburndale, MA\n" + "Babson Park, MA\n" + "Belmont, MA\n" + "Boston, MA\n" + "Brighton, MA\n" + "Brookline, MA\n" + "Cambridge, MA\n" + "Charlestown, MA\n" + " \n" + "Chestnut Hill, MA\n" + "Jamaica Plain, MA\n" + "Medford, MA\n" + "Needham, MA\n" + "New Town, MA\n" + "Newton Center, MA\n" + "Newton Highlands, MA\n" + "Newton Lower Falls, MA\n" + "Newton Upper Falls, MA\n" + "Newton, MA\n" + "Newtonville, MA\n" + " \n" + "Roslindale, MA\n" + "Sheffield, MA\n" + "Somerville, MA\n" + "South Egremont, MA\n" + "Waban, MA\n" + "Waltham, MA\n" + "Watertown, MA\n" + "Wellesley Hills, MA\n" + "Wellesley, MA\n" + "West Newton, MA\n" + "Michigan\n\n" + "Ann Arbor, MI\n" + "Birmingham, MI\n" + "Bloomfield Hills, MI\n" + "Chelsea, MI\n" + "Commerce Township, MI\n" + "Dexter, MI\n" + "Farmington, MI\n" + " \n" + "Franklin, MI\n" + "Keego Harbor, MI\n" + "Novi, MI\n" + "Plymouth, MI\n" + "Rochester, MI\n" + "Royal Oak, MI\n" + "Saline, MI\n" + " \n" + "Southfield, MI\n" + "Troy, MI\n" + "Walled Lake, MI\n" + "Waterford, MI\n" + "West Bloomfield, MI\n" + "Ypsilanti, MI\n" + "Minnesota\n\n" + "Hopkins, MN\n" + " \n" + "Minneapolis, MN\n" + " \n" + "Saint Paul, MN\n" + "New Jersey\n\n" + "Bloomfield, NJ\n" + "Caldwell, NJ\n" + "Cedar Grove, NJ\n" + "Clifton, NJ\n" + "Elmwood Park, NJ\n" + "Fair Lawn, NJ\n" + "Fairfield, NJ\n" + "Garfield, NJ\n" + " \n" + "Haledon, NJ\n" + "Lincoln Park, NJ\n" + "Little Falls, NJ\n" + "Montclair, NJ\n" + "New York, NJ\n" + "Nutley, NJ\n" + "Passaic, NJ\n" + "Paterson, NJ\n" + " \n" + "Pequannock, NJ\n" + "Rutherford, NJ\n" + "Saddle Brook, NJ\n" + "Totowa, NJ\n" + "Verona, NJ\n" + "Wayne, NJ\n" + "New York\n\n" + "Amenia, NY\n" + "Ancramdale, NY\n" + "Arverne, NY\n" + "Astoria, NY\n" + "Bayside, NY\n" + "Bellerose, NY\n" + "Breezy Point, NY\n" + "Brooklyn, NY\n" + "Cambria Heights, NY\n" + "College Point, NY\n" + "Copake, NY\n" + "Corona, NY\n" + "East Elmhurst, NY\n" + "Elmhurst, NY\n" + "Far Rockaway, NY\n" + "Flushing, NY\n" + " \n" + "Forest Hills, NY\n" + "Fresh Meadows, NY\n" + "Hollis, NY\n" + "Howard Beach, NY\n" + "Jackson Heights, NY\n" + "Jamaica, NY\n" + "Kew Gardens, NY\n" + "Little Neck, NY\n" + "Long Island City, NY\n" + "Maspeth, NY\n" + "Middle Village, NY\n" + "Millerton, NY\n" + "New York, NY\n" + "Oakland Gardens, NY\n" + "Ozone Park, NY\n" + "Pine Plains, NY\n" + " \n" + "Queens Village, NY\n" + "Rego Park, NY\n" + "Richmond Hill, NY\n" + "Ridgewood, NY\n" + "Rockaway Park, NY\n" + "Rosedale, NY\n" + "Saint Albans, NY\n" + "South Ozone Park, NY\n" + "South Richmond Hill, NY\n" + "Springfield Gardens, NY\n" + "Sunnyside, NY\n" + "Whitestone, NY\n" + "Woodhaven, NY\n" + "Woodside, NY\n" + "Oregon\n\n" + "Beaverton, OR\n" + "Hillsboro, OR\n" + " \n" + "Lake Oswego, OR\n" + "Portland, OR\n" + " \n" + "Tualatin, OR\n" + "West Linn, OR\n" + "Pennsylvania\n\n" + "Abington, PA\n" + "Ambler, PA\n" + "Ardmore, PA\n" + "Bala Cynwyd, PA\n" + "Bensalem, PA\n" + "Berwyn, PA\n" + "Blue Bell, PA\n" + "Bridgeport, PA\n" + "Bryn Athyn, PA\n" + "Bryn Mawr, PA\n" + "Cheltenham, PA\n" + "Collegeville, PA\n" + "Conshohocken, PA\n" + "Devon, PA\n" + "Dresher, PA\n" + "Drexel Hill, PA\n" + "Elkins Park, PA\n" + " \n" + "Flourtown, PA\n" + "Fort Washington, PA\n" + "Gladwyne, PA\n" + "Glenside, PA\n" + "Gwynedd Valley, PA\n" + "Gwynedd, PA\n" + "Haverford, PA\n" + "Havertown, PA\n" + "Huntingdon Valley, PA\n" + "Jenkintown, PA\n" + "King Of Prussia, PA\n" + "Lafayette Hill, PA\n" + "Lansdale, PA\n" + "Lansdowne, PA\n" + "Malvern, PA\n" + "Merion Station, PA\n" + "Mont Clare, PA\n" + " \n" + "Montgomeryville, PA\n" + "Narberth, PA\n" + "Norristown, PA\n" + "North Wales, PA\n" + "Oreland, PA\n" + "Paoli, PA\n" + "Philadelphia, PA\n" + "Phoenixville, PA\n" + "Plymouth Meeting, PA\n" + "Upper Darby, PA\n" + "Villanova, PA\n" + "Wayne, PA\n" + "Willow Grove, PA\n" + "Wyncote, PA\n" + "Wynnewood, PA\n" + "Texas\n\n" + "Austin, TX\n" + "Bellaire, TX\n" + "Cedar Park, TX\n" + "Conroe, TX\n" + " \n" + "Houston, TX\n" + "Katy, TX\n" + "Pflugerville, TX\n" + "Round Rock, TX\n" + " \n" + "Sandy, TX\n" + "Spring, TX\n" + "Virginia\n\n" + "Alexandria, VA\n" + "Arlington, VA\n" + " \n" + "Dunn Loring, VA\n" + "Falls Church, VA\n" + " \n" + "Ft Myer, VA\n" + "McLean, VA\n" + "Washington\n\n" + "Bellevue, WA\n" + "Kirkland, WA\n" + "Lynnwood, WA\n" + " \n" + "Medina, WA\n" + "Mercer Island, WA\n" + "Mountlake Terrace, WA"; 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