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

/
/
gx

Test String

Code Generator

Language

Generated Code

const regex = /(?<callsign>\w+?)>APRS,.+?, (?<receiver>\w+):\/ (?<time>\d{6})h (?<latitude>\d{4}\.\d{2}[NS]). (?<longitude>\d{5}\.\d{2}[EW]). (?:(?<heading>\d{3})\/(?<ground_speed>\d{3}))?.*? \/A=(?<altitude>\d{6})\s (?:!W((?<latitude_enhancement>\d)(?<longitude_enhancement>\d))!)? (?:v(?<version>\d+\.\d+\.\d+)(?:\.(?<platform>.+?))?\s)? CPU:(?<cpu_load>[\d.]+)\s RAM:(?<ram_free>[\d.]+)\/(?<ram_total>[\d.]+)MB\s NTP:(?<ntp_offset>[\d.]+)ms\/(?<ntp_correction>[+-][\d.]+)ppm\s? (?:(?<cpu_temperature>[+-][\d.]+)C\s*)? (?:RF: (?: (?<manual_correction>[+-][\d]+) (?<automatic_correction>[+-][\d.]+)ppm\/ )? (?<signal>[+-][\d.]+)dB )?/g; // Alternative syntax using RegExp constructor // const regex = new RegExp('(?<callsign>\\w+?)>APRS,.+?, (?<receiver>\\w+):\\\/ (?<time>\\d{6})h (?<latitude>\\d{4}\\.\\d{2}[NS]). (?<longitude>\\d{5}\\.\\d{2}[EW]). (?:(?<heading>\\d{3})\\\/(?<ground_speed>\\d{3}))?.*? \\\/A=(?<altitude>\\d{6})\\s (?:!W((?<latitude_enhancement>\\d)(?<longitude_enhancement>\\d))!)? (?:v(?<version>\\d+\\.\\d+\\.\\d+)(?:\\.(?<platform>.+?))?\\s)? CPU:(?<cpu_load>[\\d.]+)\\s RAM:(?<ram_free>[\\d.]+)\\\/(?<ram_total>[\\d.]+)MB\\s NTP:(?<ntp_offset>[\\d.]+)ms\\\/(?<ntp_correction>[+-][\\d.]+)ppm\\s? (?:(?<cpu_temperature>[+-][\\d.]+)C\\s*)? (?:RF: (?: (?<manual_correction>[+-][\\d]+) (?<automatic_correction>[+-][\\d.]+)ppm\\\/ )? (?<signal>[+-][\\d.]+)dB )?', 'g') const str = `LKHS>APRS,TCPIP*,qAC,GLIDERN2:/211635h4902.45NI01429.51E&000/000/A=001689 v0.2.4.ARM CPU:0.2 RAM:777.7/972.2MB NTP:3.1ms/-3.8ppm +33.6C RF:+62-0.8ppm/+33.66dB Moosburg>APRS,TCPIP*,qAC,GLIDERN1:/232205h4827.52NI01155.89E&000/000/A=001397 v0.2.4.ARM CPU:0.8 RAM:788.7/1017.6MB NTP:16000.0ms/-73.4ppm RF:+8.00dB`; // Reset `lastIndex` if this regex is defined globally // regex.lastIndex = 0; let m; while ((m = regex.exec(str)) !== null) { // This is necessary to avoid infinite loops with zero-width matches if (m.index === regex.lastIndex) { regex.lastIndex++; } // The result can be accessed through the `m`-variable. m.forEach((match, groupIndex) => { console.log(`Found match, group ${groupIndex}: ${match}`); }); }

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 JavaScript, please visit: https://developer.mozilla.org/en/docs/Web/JavaScript/Guide/Regular_Expressions