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 = /(?<key>[^,]+)=(?<value>[^,]+)/gm; // Alternative syntax using RegExp constructor // const regex = new RegExp('(?<key>[^,]+)=(?<value>[^,]+)', 'gm') const str = `X0=80,X1=80,X2=80,X3=80,X4=80,X5=80,X6=80,X7=80,X8=80,X9=80,X10=80,X11=80,X12=80,X13=80,X14=80,X15=80,X16=80,X17=80,X18=80,X19=80,X20=80,X21=80,X22=80,X23=80,X24=80,X25=80,X26=80,X27=80,X28=80,X29=80,X30=80,X31=80,X32=80,X33=80,X34=80,X35=80,X36=80,X37=80,X38=80,X39=80,X40=80,X41=80,X42=80,X43=80,X44=80,X45=80,X46=80,X47=80,X48=80,X49=80,X50=80,X51=80,X52=80,X53=80,X54=80,X55=80,X56=80,X57=80,X58=80,X59=80,X60=80,X61=80,X62=80`; // 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