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

/
/
gmix

Test String

Code Generator

Generated Code

const regex = /\$ (?=[^$]{3,100}\$) (?<PH>[A-Za-z0-9:_-]{1,20}) (?: (?<C1>\/) (?<RX>(?:[^\\\/\r\n]|\\\/?)*) \/ (?: (?<R>(?:[^\\\/\r\n$]|\\[\/$]?)*) \/ | (?<G>\d*) ) | (?: (?<C2>\() (?<F>(?:[^\t\r\n\f()]|\\[()]?)*) \) )? ) \$/gmi; // Alternative syntax using RegExp constructor // const regex = new RegExp('\\$ (?=[^$]{3,100}\\$) (?<PH>[A-Za-z0-9:_-]{1,20}) (?: (?<C1>\\\/) (?<RX>(?:[^\\\\\\\/\\r\\n]|\\\\\\\/?)*) \\\/ (?: (?<R>(?:[^\\\\\\\/\\r\\n$]|\\\\[\\\/$]?)*) \\\/ | (?<G>\\d*) ) | (?: (?<C2>\\() (?<F>(?:[^\\t\\r\\n\\f()]|\\\\[()]?)*) \\) )? ) \\$', 'gmi') const str = ` \$EX1\$ -> EX1 \$EX2(a\$b\$c)\$ -> EX2, (, a\$b\$c \$EX3(abc\\x/)\$ -> EX3, (, abc\\x/ \$EX4(\\@\\,/&/)\$ -> EX4, (, \\@\\,/&/ \$EX5/X(Z)Y/\$ -> EX5, /, X(Z)Y \$EX6/X(ABC)/1\$ -> EX6, /, X(ABC), 1 \$EX7/X\\\\Z\\/Y/\$ -> EX7, /, X\\\\Z\\/Y \$EX8/(A)/(B)/\$ -> EX8, /, (A), (B) \$EX9/(\\\\\$A\$)\\//(\\\\\$B\$\\/)/\$ -> EX9, /, (\\\\\$A\$)\\/, (\\\\\$B\$\\/) Lorem Ip\$um \$EX1\$i\$ simply dummy \$EX1\$\$EX2(abc)\$ te\$t of the printing and type\$EX2(abc)\$etting indu\$try. \$EX3(abc\\x/)\$ Lorem \$EX4(\\@\\,/&/)\$Ipsum has been the industry'\$EX5/X(Z)Y/\$ standard du\$EX6/X(ABC)/1\$mmy text \$EX7/X\\\\Z\\/Y/\$ ever \$\$\$ince the 1500\$EX8/(A)/(B)/\$, when an \$ unknown \$EX9/(\\\\\$A\$)\\//(\\\\\$B\$\\/)/\$ printer took a galley of type `; // 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