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

$re = '/^(?:<#.*?#>|[^#])*(#.*)?/m'; $str = '----------------- ---MATCH CASES--- ------------------------------------------------ $text = "Hello"\\t# Comment after tab $text+= #Comment without space after hash Write-Host $text# Comment without space before hash #Comment line with no whitespaces around\' Write-Host "Hello"#Comment in the end with no whitespaces around\' # Comment with whitespaces around \' # Consecutive comments # Last line comment without line ending in the end $text+= #Comment with < inside $text+= #Comment ending with > $text+= #Comment with <# inline comment #> # Normal comment Write-Host "Comment without text" # An <# inline comment #> preceding a #comment An <# inline # comment containing a # #> preceding a #comment Two <# inline #> comments <# to be #> skipped # comment -------------------- ---NO MATCH CASES--- ------------------------------------------------ Write-Host "Hello" Write-Host "World" Write-Host "Non-empty line" $text = "Hello" <# block comment #> + "World" $text = "Hello" +<#comment#>"World" <# Block comment in a line #> Write-Host "Hello world <# Block comment in the end of line #>'; preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0); // Print the entire match result var_dump($matches);

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 PHP, please visit: http://php.net/manual/en/ref.pcre.php