PHP regular expressions: No ending delimiter '^' found in

Question

I've been having some trouble with regular expressions.

This is my code

$pattern = "^([0-9]+)$";

if (preg_match($pattern, $input))
   echo "yes";
else
   echo "nope";

I run it and get:

Warning: preg_match() [function.preg-match]: No ending delimiter '^' found in

Solution 1

PHP regex strings need delimiters. Try:

$numpattern="/^([0-9]+)$/";

Also, note that you have a lower case o, not a zero. In addition, if you're just validating, you don't need the capturing group, and can simplify the regex to /^\d+$/.

Example: http://ideone.com/Ec3zh

See also: PHP - Delimiters

Solution 2

Your regex pattern needs to be in delimiters:

$numpattern="/^([0-9]+)$/";

Solution 3

You can use T-Regx library, that doesn't need delimiters

pattern('^([0-9]+)$')->match($input);

Comments

[greenoldman]

For those who do not read linked materials, use [ and ] delimiters, otherwise you run into conflicts with the pattern itself.

[MartinNajemi]

Why would you use an additional library? Just encase the regex in '/'

[Danon]

@MartinNajemi It's just a suggestion. The first accepted answer suggests enclosing with delimiters "/", and my answer suggests using an alternative. There's no point in posting two similar answers.