用逗号表示PHP中的正则表达式

Question

I'm trying to extract mark-up from a string. I'm part way there but am having trouble with commas in my pattern.

Take this example input string :

 Lorem ipsum dolor sit amet, <that index="8"/>consectetur adipiscing elit. <that index="4"/>Sed metus sem, facilisis id nibh eget, <that index="6,2"/>accumsan tristique nisl. Proin iaculis dignissim tincidunt.I said : <that index="9,1"/>

I wish to extract the tags including the attribute 'index'.

I need both variations, ie patterns without and with commas in the attribute.

If I do this :

$haystack = 'Lorem ipsum dolor sit amet, <that index="8"/>consectetur adipiscing elit. <that index="4"/>Sed metus sem, facilisis id nibh eget, <that index="6,2"/>accumsan tristique nisl. Proin iaculis dignissim tincidunt.I said : <that index="9,1"/>';
$regex = '<that index="[0-9,]"\/>';
preg_match_all ( '/' . $regex . '/i', $haystack, $thats );

The array $thats only contains this :

(
[0] => Array
    (
        [0] => <that index="8"/>
        [1] => <that index="4"/>
    )

)

So clearly I am doing something wrong with how I use the comma in the pattern, because it omits those with commas.

Could someone please advise. Thank you.

Answer 1

Add + after the character class to match one or more characters in the given list.

$regex = '<that index="[0-9,]+"\/>';
preg_match_all ( '/' . $regex . '/i', $haystack, $thats );

DEMO