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 = /(^\|(\s*[A-Z][A-Z_]*\s*\|)+\s*$)\r?\n(^\|([\s-]+\|)+\s*$)/gm; // Alternative syntax using RegExp constructor // const regex = new RegExp('(^\\|(\\s*[A-Z][A-Z_]*\\s*\\|)+\\s*$)\\r?\\n(^\\|([\\s-]+\\|)+\\s*$)', 'gm') const str = `Which SQL query will help you fetch the department ID and department name for departments where the number of employees exceeds 10? | EMP_ID | F_NAME | L_NAME | SALARY | DEPT_ID_DEP | | --- | --- | --- | --- | --- | | 1 | John | Doe | 60000 | 101 | | 2 | Jane | Smith | 75000 | 102 | | 3 | Emily | Davis | 80000 | 101 | | 4 | Michael | Johnson | 65000 | 103 | | DEP_ID | DEP_NAME | MANAGER_ID | LOCATION_ID | | --- | --- | --- | --- | | 101 | IT | 10 | L0001 | | 102 | HR | 20 | L0002 | | 103 | Finance | 30 | L0003 | | 104 | Marketing | 40 | L0004 |`; // 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