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

/
/
gmiU

Test String

Code Generator

Language

Generated Code

const regex = /[ ^\s]([ ]{1,})[ ^\s]/gmi; // Alternative syntax using RegExp constructor // const regex = new RegExp('[ ^\\s]([ ]{1,})[ ^\\s]', 'gmi') const str = `5382948 EGELSTON^ELIZABETH 0102126763 1942-09-17 00:00:00.000 F 2003-02-09 00:00:00.000 1899-12-30 19:39:10.000 CT03011350 28465 1.2.124.113532.10.7.222.5.20030209.190851.3087742 NULL UNKNOWN^RADNET CT NULL PE CHEST 764A NULL BODY Northwestern Memorial Hosp. NMH5_OC0 NULL NULL NULL 4 467 544 NULL 2003-04-27 22:56:55.000 NULL 2003-04-27 23:14:42.000 8 2009-06-07 09:22:07.640 2015-11-14 03:54:07.407 2015-11-14 03:54:08.290 NULL NULL CT NULL 5706865 5382948 CT 1.2.840.113619.2.55.1.1762864829.1989.1044811980.588.5 5 Recon 2: ROUTINE PE NULL 5.7 ROUTINE PE NULL 1.2.124.113532.10.7.222.5.20030209.190851.3087742.9814.0.12 4 200 NULL NULL NULL 8 NULL NULL NULL 7276786 5706865 3 NULL 4 NULL 0102126763\\1_2_124_113532_10_7_222_5_\\7276786.0 NULL 289158 NULL 3 ASP_NMH_99_LIB2 \\\\asp1nsx02\\ASP_NMH_99_LIB2\\Incoming \\\\asp1nsx02\\ASP_NMH_99_LIB2\\Images LOCAL`; // 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