Regular Expressions 101

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Library entries

-20
javascript

validating email

no description available
Submitted by niyas - 9 years ago
-18
javascript

www.medibank.com.au

no description available
Submitted by anonymous - 7 years ago
-13
javascript

Haha !

no description available
Submitted by Alex - 8 years ago
-9
javascript

<script>alert(1)</script>

alert(1)alert(1)
Submitted by <script>alert(1)</script> - 8 years ago
-7
javascript

Javascipt variable

Matches a javascript variable
Submitted by Andres Jorquera - 8 years ago
-6
javascript

n.o

nao
Submitted by Flávio - 8 years ago
-4
javascript

email

no description available
Submitted by public - 8 years ago
-4
javascript

Hallo

no description available
Submitted by anonymous - 8 years ago
-4
javascript

Email with + symbol

email that accepts the plus (+) symbol
Submitted by luckcheese - 7 years ago
-3
javascript

s

s
Submitted by anonymous - 8 years ago
-3
javascript

1111

no description available
Submitted by anonymous - 8 years ago
-3
javascript

111

no description available
Submitted by anonymous - 8 years ago
-3
javascript

111

no description available
Submitted by anonymous - 8 years ago
-3
javascript

Detect a numeric string

no description available
Submitted by Ankur Chauhan - 8 years ago

match valid JSON

Vote

26

Regular Expression
pcre

/
(?(DEFINE) # Note that everything is atomic, JSON does not need backtracking if it's valid # and this prevents catastrophic backtracking (?<json>(?>\s*(?&object)\s*|\s*(?&array)\s*)) (?<object>(?>\{\s*(?>(?&pair)(?>\s*,\s*(?&pair))*)?\s*\})) (?<pair>(?>(?&STRING)\s*:\s*(?&value))) (?<array>(?>\[\s*(?>(?&value)(?>\s*,\s*(?&value))*)?\s*\])) (?<value>(?>true|false|null|(?&STRING)|(?&NUMBER)|(?&object)|(?&array))) (?<STRING>(?>"(?>\\(?>["\\\/bfnrt]|u[a-fA-F0-9]{4})|[^"\\\0-\x1F\x7F]+)*")) (?<NUMBER>(?>-?(?>0|[1-9][0-9]*)(?>\.[0-9]+)?(?>[eE][+-]?[0-9]+)?)) ) \A(?&json)\z
/
x

Description

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Submitted by Mateon1 - 8 years ago