php regex / preg_match

Question

I'm trying to match the numbers inside ('')

$linkvar ="<a onclick="javascript:open('597967');" class="links">more</a>"


preg_match("^[0-9]$",$linkvar,$result); 

Answer 1

Your regex only matches if the entire string is made up of one number because of the ^ and $ modifiers. Your current regex translates in human language to:

1. ^ means "this is the start of the string"
2. [0-9] means "match a single numeric character"
3. $ means "this is the end of the string"

Change it to:

preg_match("[0-9]+",$linkvar,$result);

Or alternatively, the shorthand syntax for matching numbers:

preg_match("\d+",$linkvar,$result);

The + modifier means that "one or more" numbers must be found in order for it to be a match.

Additionally, if you want to actually capture the numbers inside the string you'll need to add parentheses to inform preg_match that you actually want to "save" the numbers.

Answer 2

Your regex will only match if the string is exactly one digit. To match only the digits inside the quotes, use:

preg_match("/'(\d+)'/", $linkvar, $result);
var_dump($result[1]);

Answer 3

The ^ and $ match the start and end of the string, which means you are currently searching for a string containing ONLY a single digit. Remove them and add a plus quantifier, leaving just "[0-9]+", and it will find the first group of digits in the string.

preg_match("[0-9]+",$linkvar,$result);