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

$re = '/^(?=[A-Za-z0-9][A-Za-z0-9@._%+-]{5,253}$)[A-Za-z0-9._%+-]{1,64}@(?:(?=[A-Za-z0-9-]{1,63}\.)[A-Za-z0-9]+(?:-[A-Za-z0-9]+)*\.){1,8}[A-Za-z]{2,63}$/m'; $str = 'Format: minimum 2 characters @ minimum 3 characters . 2 - 63 characters the g modifier let\'s us match multiple times in one string. the m modifier is useful here because it lets us treat each line as a seperate entry. Though in practice you probably dont need it for a simple one line email field ^(?=[A-Z0-9][A-Z0-9@._%+-]{5,253}+$)[A-Z0-9._%+-]{1,64}+@(?:(?=[A-Z0-9-]{1,63}+\\.)[A-Z0-9]++(?:-[A-Z0-9]++)*+\\.){1,8}+[A-Z]{2,63}+$ שדגכ@שדגכ דגכ אלפ@גכדץ.בםצ Jim@stuff.co.uk Jim@google.com Henry@h.com Joe @m.net Joe@m.net Joe@mo.net Joe@sam.net a@sam.net mo@sam.org 12@sam.org Jon@sam.c Jon@sam.co '; 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