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 = /(?:<(?:p)\b[^>]*?color\s*:\s*(?:(black))[^>]*?>(?(1)(?:\s*<span\b[^>]*?>)?)|<span\b[^>]*?color\s*:\s*black[^>]*?>)(?s)\s*<code\b(?:".*?"|'.*?'|[^>]*?)+>(*SKIP)(*FAIL)|<code\b[^>]*?style[^>]*?background-color\s*:\s*transparent[^>]*?>/gm; // Alternative syntax using RegExp constructor // const regex = new RegExp('(?:<(?:p)\\b[^>]*?color\\s*:\\s*(?:(black))[^>]*?>(?(1)(?:\\s*<span\\b[^>]*?>)?)|<span\\b[^>]*?color\\s*:\\s*black[^>]*?>)(?s)\\s*<code\\b(?:".*?"|\'.*?\'|[^>]*?)+>(*SKIP)(*FAIL)|<code\\b[^>]*?style[^>]*?background-color\\s*:\\s*transparent[^>]*?>', 'gm') const str = `<html> <p style="font-family: &quot;verdana&quot;; font-size: 18px; color: black; line-height: 18px; text-align: justify; font-style: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; background-color: cyan;"><span style="font-size: 13.5pt; font-family: &quot;Verdana&quot;,&quot;sans-serif&quot;;"><code style="background-color: transparent;"><b>some text here</b></code></span></p> <span><span style="font-size: 13.5pt; font-family: &quot;Verdana&quot;,&quot;sans-serif&quot;; background-color: cyan;"><code style="background-color: transparent;"><b>some text here</b></code></span> <code style="background-color: transparent;"> <p style="font-family: &quot;verdana&quot;; font-size: 18px; color: cyan; line-height: 18px; text-align: justify; font-style: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; background-color: cyan;"><span style="color: black; font-size: 13.5pt; font-family: &quot;Verdana&quot;,&quot;sans-serif&quot;;"><code style="background-color: transparent;"><b>some text here</b></code></span></p> <span><span style="font-size: 13.5pt; font-family: &quot;Verdana&quot;,&quot;sans-serif&quot;; background-color: cyan;"><code style="background-color: transparent;"><b>some text here</b></code></span> <p style="font-family: &quot;verdana&quot;; font-size: 18px; color: cyan; line-height: 18px; text-align: justify; font-style: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; background-color: navy;"><span style="font-size: 13.5pt; font-family: &quot;Verdana&quot;,&quot;sans-serif&quot;;"><code style="background-color: transparent;"><b>some text here</b></code></span></p> </html>`; // 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