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

/
/
gi

Test String

Code Generator

Generated Code

$re = '/<script\b[^<]*(?:(?!<\/script>)<[^<]*)*<\/script\s*>/i'; $str = 'So, let’s imagine that we have to check a text field, and there’s no particular information about it in project specifications. In this case, it’s possible to do the following: Click on the Submit button without previous text field filling. Click on the space bar a few times, and then click on the Submit button. Analyze how many characters you can enter in the field, and then press the Submit button. Enter the minus sign and as many numbers as you can, and then tap Submit. Enter all the possible special symbols and click Submit. If you see a message with an error, try to analyze it. Try to enter the symbols that don’t technically correspond with ASCII, different emoji icons, and click Submit. If you see a message with an error, try to analyze it. Try the features of the cross-site scripting. For this, you should enter such a script: <SCRIPT>alert(“I hacked this!”)</SCRIPT>. If there is a pop-up after clicking Submit, it means that this field is vulnerable to XSS attack (cross-site scripting attack). Check if it’s possible to use SQL injections. Enter FOO’); DROP TABLE USERS. But don’t do this with databases of those sites that are in production.'; preg_match_all($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