Question

I am not very good at regular expressions. Can somebody help me with this?

$string = '1,2,3,4,7,8,10,11,14,17,18,19,22,23,26,29,30';

preg_match('/(\d*,*)(2,)(\d*,*)(4,)(\d*,*)(8)/', $string);

All the time this string has to be string, can’t be array or anything else. Let’s say I am looking for numbers 2, 4, 8 (but not 18). I am using PHP and the preg_match function.

Answer 1

Here is solution with array:

// explode a string to array of numbers
$haystack = explode(',', $string);
// define numbers to search
$needle = array(2,4,48);
// define found elements
$found = array_intersect($needle, $haystack);
// print found elements
if ($found) {
    print 'Found: ' . implode(',', $found);
}

And solution with preg_match:

// add "," to the beginning and string end
$string = ",$string,";
// define pattern to search (search for 14, 19 or 20)
$pattern = '/,14|19|20,/';
// if pattern is found then display Hello
if (preg_match($pattern, $string)) {
    print 'Hello';
}