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 = /intensity\"\s*:\s*\(\"\w+\"\s*:\s*(?<intensity>\d+)/gm; // Alternative syntax using RegExp constructor // const regex = new RegExp('intensity\\"\\s*:\\s*\\(\\"\\w+\\"\\s*:\\s*(?<intensity>\\d+)', 'gm') const str = `("data": ["from" : "2024-04-25T11: 30Z", "to": "2024-04-2512:00Z", "intensity": ("forecast": 152, "actual": null, "index": "moderate"}), ("from": "2024-04-25T12:002", "intensity": {"forecast": 152, "actual": null, "index": "moderate"}), ("from": "2024-04-25T12:30Z", "to": {"from": "2024-04-25T13:00Z", "to": "2024-04-25T12: 30Z", ("forecast": 164, "actual": null, "2024-04-2513: 30Z", "intensity": ("forecast": 154, "to": "2024-04-25T13: 002", "intensity": ("forecast": 154, "actual": null, "index": "actual": null, "index": "moderate"}), ("from": "2024-04-25T13:30Z*, "to": "2024-04-25T14:002", "moderate"}}, "intensity"： 04-25T14: 30Z", "to" : "index": "moderate"3}, ("from": "2024-04-25T14:002*, "to": "2024-04-25T14:30Z", "intensity": ("forecast": 166, "actual": null, "index": "moderate"}), ("from": " 2024-04-25T15:00Z" "actual": nu11, "index" "intensity": {"forecast": 170, "actual": null, "index": "moderate"}), {"from": "2024-04-2515: 00Z", 2024- "to" : "moderate"}), {"from": "2024-04-25T15:30Z", "to": "2024-04-25T16:00Z", "intensity": ("forecast": 175, "to": "2024-04-25T15: 30Z", "intensity": {"forecast": 172, "2024-04-25T16: 30Z", "index": "moderate"}}, ("from": "2024-04-25T17:00Z", "to": "intensity": ("forecast": 177, "actual": null, "index": "moderate"?), ("from": "2024-04-2516: 302", "actual" : nu11, "index" "moderate"}}, ("from": "2024-04-2516: 00Z", "to": "2024-04-25T17:002", "intensity": ("forecast": 179, "actual": null, 2024-04-2517: 30Z", "intensity": ("forecast": 181, "actual": null, 25T18:00Z", "intensity": ("forecast": 184, "index": "moderate"}}, {"from": "2024-04-25T17: 30Z", "actual": null, "index": "moderate"}), ("from": "2024-04-25T18:002", "to": "2024-04-25T18: 30Z", "to": "2024-04- "moderate"}}, ("from": "2024-04-2518: 30Z", "to": "2024-04-25T19:002", "intensity": ("forecast": 187, "actual": null, "intensity": ("forecast": 190, "actua1": nul1, "index": "index": "high"}}, ("from": "intensity": {"forecast": 193, "actual": null, "index": "2024-04-25T19: 00Z", "to": "2024-04-25T19: 30Z" "high"}}, ("from": "2024-04-25T19:30Z", "to": "2024-04-25T20:00Z", "intensity": {"forecast": 194, "2024-04-2520: 00Z", "to": "2024-04-25T20:30Z", "intensity": {"forecast": 195, "actual": null, "index": "high"3}, ("from": "2024-04-25T20:30Z", "actual": null, "index": "high")}, ("from": "2024-04-25T21:00Z", "intensity": ("forecast": 198, "actual": null, "index": "high"'), ("from": "2024-04-25T21: 002", "2024-04-25T22: 00Z", "intensity": {"forecast": 187, "actual": null, "to": "2024-04-25T21: 30Z", "intensity": {"forecast": 196, 'actual": null, "index": "high"}}, {"from": "2024-04-25T21:302" "to" "index": "moderate"}}, ("from": "2024-04-25T22:00Z", "to": "2024-04-25T22: 30Z", "intensity": ("forecast": 181, "actual": null, "index": "moderate"}}, {"from": "2024-04-25T22:30Z", "to": "2024-04-25T23:002", "intensity": ("forecast": 180, "actual": null, "index' moderate"｝｝，｛"from"： 25T23:30Z", "intensity": {"forecast": 172, "actual": null, "index": "moderate"}}, {"from": "2024-04-25T23: 30Z", "2024-04-25T23:002", "to": " 2024-04- "moderate"}}, {"from": "2024-04-26T00:00Z", "to": "2024-04-2600: 30Z", "intensity": ("forecast": 150, "to": "2024-04-2600: 00Z", "intensity": ("forecast": 150, "actual": null, "index": "actual": null, "index": "moderate")}, ("from": "2024-04-26T00: 302", "to": "2024-04-26T01:00Z" "intensity": {"forecast": 149, "actual": null, "index": "moderate"}}, ("from": "2024-04-26T01:002", "to": "2024-04-26T01:30Z", "intensity": {"forecast": 149, "actual": null, "index": "moderate"}}, ...`; // 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