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

const regex = /^\s*($|#|\w+\s*=|(\?|\*|(?:[0-5]?\d)(?:(?:-|\/|\,)(?:[0-5]?\d))?(?:,(?:[0-5]?\d)(?:(?:-|\/|\,)(?:[0-5]?\d))?)*)\s+(\?|\*|(?:[0-5]?(?:\d|\*))(?:(?:-|\/|\,)(?:[0-5]?\d))?(?:,(?:[0-5]?\d)(?:(?:-|\/|\,)(?:[0-5]?\d))?)*)\s+(\?|\*|(?:[01]?(?:\d|\*)|2[0-3])(?:(?:-|\/|\,)(?:[01]?\d|2[0-3]))?(?:,(?:[01]?\d|2[0-3])(?:(?:-|\/|\,)(?:[01]?\d|2[0-3]))?)*)\s+(\?|\*|(?:0?[1-9]|[12]\d|3[01]|\*)(?:(?:-|\/|\,)(?:0?[1-9]|[12]\d|3[01]))?(?:,(?:0?[1-9]|[12]\d|3[01])(?:(?:-|\/|\,)(?:0?[1-9]|[12]\d|3[01]))?)*|(?:L)|(?:LW)|(?:L-(?:[0-9]|1\d|2\d|30))|(?:\dW|1\dW))\s+(\?|\*|(?:[1-9]|1[012])(?:(?:-|\/|\,)(?:[1-9]|1[012]))?(?:L|W)?(?:,(?:[1-9]|1[012])(?:(?:-|\/|\,)(?:[1-9]|1[012]))?(?:L|W)?)*|\?|\*|(?:JAN|FEB|MAR|APR|MAY|JUN|JUL|AUG|SEP|OCT|NOV|DEC)(?:(?:-)(?:JAN|FEB|MAR|APR|MAY|JUN|JUL|AUG|SEP|OCT|NOV|DEC))?(?:,(?:JAN|FEB|MAR|APR|MAY|JUN|JUL|AUG|SEP|OCT|NOV|DEC)(?:(?:-)(?:JAN|FEB|MAR|APR|MAY|JUN|JUL|AUG|SEP|OCT|NOV|DEC))?)*)\s+(\?|\*|(?:[1-7])(?:(?:-|\/|\,|#)(?:[1-7]))?(?:L)?(?:,(?:[1-7])(?:(?:-|\/|\,|#)(?:[1-7]))?(?:L)?)*|\?|\*|(?:MON|TUE|WED|THU|FRI|SAT|SUN)(?:(?:-)(?:MON|TUE|WED|THU|FRI|SAT|SUN))?(?:,(?:MON|TUE|WED|THU|FRI|SAT|SUN)(?:(?:-)(?:MON|TUE|WED|THU|FRI|SAT|SUN))?)*)(|\s)+(\?|\*|(?:|\d{4})(?:(?:-|\/|\,)(?:|\d{4}))?(?:,(?:|\d{4})(?:(?:-|\/|\,)(?:|\d{4}))?)*))$/gm; // Alternative syntax using RegExp constructor // const regex = new RegExp('^\\s*($|#|\\w+\\s*=|(\\?|\\*|(?:[0-5]?\\d)(?:(?:-|\\\/|\\,)(?:[0-5]?\\d))?(?:,(?:[0-5]?\\d)(?:(?:-|\\\/|\\,)(?:[0-5]?\\d))?)*)\\s+(\\?|\\*|(?:[0-5]?(?:\\d|\\*))(?:(?:-|\\\/|\\,)(?:[0-5]?\\d))?(?:,(?:[0-5]?\\d)(?:(?:-|\\\/|\\,)(?:[0-5]?\\d))?)*)\\s+(\\?|\\*|(?:[01]?(?:\\d|\\*)|2[0-3])(?:(?:-|\\\/|\\,)(?:[01]?\\d|2[0-3]))?(?:,(?:[01]?\\d|2[0-3])(?:(?:-|\\\/|\\,)(?:[01]?\\d|2[0-3]))?)*)\\s+(\\?|\\*|(?:0?[1-9]|[12]\\d|3[01]|\\*)(?:(?:-|\\\/|\\,)(?:0?[1-9]|[12]\\d|3[01]))?(?:,(?:0?[1-9]|[12]\\d|3[01])(?:(?:-|\\\/|\\,)(?:0?[1-9]|[12]\\d|3[01]))?)*|(?:L)|(?:LW)|(?:L-(?:[0-9]|1\\d|2\\d|30))|(?:\\dW|1\\dW))\\s+(\\?|\\*|(?:[1-9]|1[012])(?:(?:-|\\\/|\\,)(?:[1-9]|1[012]))?(?:L|W)?(?:,(?:[1-9]|1[012])(?:(?:-|\\\/|\\,)(?:[1-9]|1[012]))?(?:L|W)?)*|\\?|\\*|(?:JAN|FEB|MAR|APR|MAY|JUN|JUL|AUG|SEP|OCT|NOV|DEC)(?:(?:-)(?:JAN|FEB|MAR|APR|MAY|JUN|JUL|AUG|SEP|OCT|NOV|DEC))?(?:,(?:JAN|FEB|MAR|APR|MAY|JUN|JUL|AUG|SEP|OCT|NOV|DEC)(?:(?:-)(?:JAN|FEB|MAR|APR|MAY|JUN|JUL|AUG|SEP|OCT|NOV|DEC))?)*)\\s+(\\?|\\*|(?:[1-7])(?:(?:-|\\\/|\\,|#)(?:[1-7]))?(?:L)?(?:,(?:[1-7])(?:(?:-|\\\/|\\,|#)(?:[1-7]))?(?:L)?)*|\\?|\\*|(?:MON|TUE|WED|THU|FRI|SAT|SUN)(?:(?:-)(?:MON|TUE|WED|THU|FRI|SAT|SUN))?(?:,(?:MON|TUE|WED|THU|FRI|SAT|SUN)(?:(?:-)(?:MON|TUE|WED|THU|FRI|SAT|SUN))?)*)(|\\s)+(\\?|\\*|(?:|\\d{4})(?:(?:-|\\\/|\\,)(?:|\\d{4}))?(?:,(?:|\\d{4})(?:(?:-|\\\/|\\,)(?:|\\d{4}))?)*))$', 'gm') const str = `* * * ? * * 0 0/1 * * * ? 0/5 14,18,3-39,52 * ? JAN,MAR,SEP MON-FRI 2002-2010 0 * * ? * * 0 */2 * ? * * 0 1/2 * ? * * 0 */3 * ? * * 0 */4 * ? * * 0 */5 * ? * * 0 */10 * ? * * 0 */15 * ? * * 0 */30 * ? * * 0 15,30,45 * ? * * 0 0 * ? * * 0 0 */2 ? * * 0 0 0/2 ? * * 0 0 1/2 ? * * 0 0 */3 ? * * 0 0 */4 ? * * 0 0 */6 ? * * 0 0 */8 ? * * 0 0 */12 ? * * 0 0 0 * * ? 0 0 1 * * ? 0 0 6 * * ? 0 0 12 * * ? 0 0 12 ? * SUN 0 0 12 ? * MON 0 0 12 ? * TUE 0 0 12 ? * WED 0 0 12 ? * THU 0 0 12 ? * FRI 0 0 12 ? * SAT 0 0 12 ? * MON-FRI 0 0 12 ? * SUN,SAT 0 0 12 */7 * ? 0 0 12 1 * ? 0 0 12 2 * ? 0 0 12 15 * ? 0 0 12 1/2 * ? 0 0 12 1/4 * ? 0 0 12 L * ? 0 0 12 L-2 * ? 0 0 12 L-12 * ? 0 0 12 L-22 * ? 0 0 12 L-30 * ? 0 0 12 LW * ? 0 0 12 1W * ? 0 0 12 15W * ? 0 0 12 ? * 2#1 0 0 12 ? * 6#1 0 0 12 ? * 2#2 0 0 12 ? * 5#3 0 0 12 ? JAN * 0 0 12 ? JUN * 0 0 12 ? JAN,JUN * 0 0 12 ? DEC * 0 0 12 ? JAN,FEB,MAR,APR * 0 0 12 ? 9-12 * 0 1 0 ? * 7 0 59 23 ? * 7,2,1,5`; // 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