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 = "\\{\"app_id\":\"(?P<appid>(?:\\w+))\",\"dev_id\":\"(?P<devid>(?:\\w+))\",\"hardware_serial\":\"(?P<hardwareserial>(?:\\w+))\",\"port\":(?P<port>(?:\\d+)),\"counter\":(?P<counter>(?:\\d+)),\"payload_raw\":\"(?P<raw>(?:(\\w+\\=|\\w+|\\w+\\==)))\",\"payload_fields\":\\{\"(?P<value>(?:\\w+))\":\"(?P<val>(?:\\d+))\"\\},\"metadata\":\\{\"time\":\"(?P<time>(?:\\w+-\\w+-\\w+:\\w+:\\w+.\\w+))\",\"frequency\":(?P<freq>(?:(\\w+.*\\w+|\\d+))),\"modulation\":\"(?P<modulation>(?:\\w+))\",\"data_rate\":\"(?P<data_rate>(?:\\w+))\",\"airtime\":(?P<airtime>(?:\\w+)),\"coding_rate\":\"(?P<coding_rate>(?:\\d+\\/\\w+))\",\"gateways\":\\[\\{\"gtw_id\":\"(?P<gtw_id>(?:(\\w+|\\w+\\-\\w+)))\"(|,\"gtw_trusted\":(?P<trusted>(?:\\w+))),\"timestamp\":(?P<timestamp>(?:\\w+)),\"time\":\"(?P<times>(?:(\\w+.\\w+.\\w+.\\w+.\\w+|\\w+.\\w+.\\w+.\\w+.\\w+.\\w+)))\",\"channel\":(?P<channel>(?:\\d+)),\"rssi\":-(?P<rssi>(?:\\d+)),\"snr\":(?P<snr>(?:(\\d+.\\d+|\\d+))),\"rf_chain\":(?P<rf_chain>(?:\\d+)),\"latitude\":(?P<latitude>(?:(\\d+.\\d+|\\d+))),\"longitude\":(?P<longitude>(?:\\b(\\d*.\\d+|\\d)\\b)),\"location_source\":\"(?P<registry>(?:\\w+))\"\\}\\]\\}\\}"; final String string = ""; 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