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

r"
"
g

Test String

Code Generator

Language

Generated Code

const regex = new RegExp('([\\w*-′]*([\\[(]([\\[(]?[a-zA-Zα-ωΑ-Ωµ\\-′,:]+\\d?[+-]?[\\])]?)+[\\])\\d+-]{1,})[\\w*-′]*)|(([A-z]+[a-z]*\\d)+([A-z]+[a-z]*\\d?)*)', 'g') const str = `"Fe(iii) or iron(iii) [Fe(Rtpen)X](A)n, n = 1, 2; X = Cl, Br; Rtpen = N-alkyl-N,N′,N′-tris(2-pyridylmethyl)ethane-1,2-diamine, alkyl = R = CH3CH2, CH3CH2CH2, HOCH2CH2, (CH3)2CH, C6H5, and C6H5CH2; A = ClO4, PF6." "iron(iii) [Fe(Rtpen)(η1-OCH3)]2+ [Fe(Rtpen)(η1-OOH)]2+ from iron(ii)" "[FeIIIOOH]2+ rather than [FeIIIOO]+ species are the p" [(Rtpen)Fe(µ,η2:η2-O2)Fe(Rtpen)]4+ iron(iii) Fe(iii) [FeIIIOOH]2+ [Fe(Rtpen)Cl]+ [Fe(Rtpen)(η1-OOH)]2+ [Fe(Rtpen)X](A)n [(Rtpen)Fe(µ,η2:η2-O2)Fe(Rtpen)]4+ Fe(Rtpen)(η2-OO)]+, N′-tris(2-pyridylmethyl)ethane-1,2-diamine of [Fe(Rtpen)(η1-OOH)]2+ pro (ESR, UV-vis, ESI MS) [Fe(Rtpen)(η1-OOH)]2+, R = CH3CH2, CH3CH2CH2, HOCH2CH2, (CH3)2CH, C6H5, and C6H5CH2. f [Fe(ettpen)Cl]ClO4 instead of [Fe(bztpen)Cl]ClO4 [Fe(Rtpen)Cl]A, A = ClO4, PF6, are as expected ESR silent. [Fe(Rtpen)Cl](PF6) and [Fe(Rtpen)Cl](PF6)2 e µ-oxo complex [(bztpen)ClFe(µ-O)FeCl(bztpen)](PF6)2 which could be isolated. H2O [Fe(bztpen)Cl](ClO4)2 solution at 100 K, a rhombic low-spin signal (g = 2.32, 2.14, 1.93) is present in the spectra of the Fe(iii) complexes (Fig. 3a) ). metpen–Fe(iii)–peroxide complexes, lead to assignment of end-on coordination for the hydroperoxide species, e.g., [Fe(Rtpen)(η1-OOH)]2+, and side-on (η2) peroxide coordination in their deprotonated derivatives, e.g., [Fe(Rtpen)(η2-OO)]+ (Scheme 1)`; // 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