Catching ids and its values from a string with preg_match

问题

I was wondering how can I create preg_match for catching:

id=4

4 being any number and how can I search for the above example in a string?

If this is could be correct /^id=[0-9]/, the reason why I'm asking is because I'm not really good with preg_match.

回答1:

for 4 being any number, we must set the range for it:

/^id\=[0-9]+/

\escape the equal-sign, plus after the number means 1 or even more.

回答2:

You should go with the the following:

/id=(\d+)/g

Explanations:

• id= - Literal id=
  
• (\d+) - Capturing group 0-9 a character range between 0 and 9; + - repeating infinite times
• /g - modifier: global. All matches (don't return on first match)

Example online

If you want to grab all ids and its values in PHP you could go with:

$string = "There are three ids: id=10 and id=12 and id=100";
preg_match_all("/id=(\d+)/", $string, $matches);
print_r($matches);

Output:

Array
(
    [0] => Array
        (
            [0] => id=10
            [1] => id=12
            [2] => id=100
        )

    [1] => Array
        (
            [0] => 10
            [1] => 12
            [2] => 100
        )

)

Example online

Note: If you want to match all you must use /g modifier. PHP doesn't support it but has other function for that which is preg_match_all. All you need to do is remove the g from the regex.

来源：https://stackoverflow.com/questions/19700380/catching-ids-and-its-values-from-a-string-with-preg-match