Check if String has only Integers separated by comma in PHP

Question

I am really empty at Regex side and that\'s why couldn\'t get how to make a Regex in PHP which checks if the string has this particular sequence of characters.

Answer 1

If you do not care about the format then you can just check for the characters:

$regex = '/^[0-9,]+$/';
if (preg_match($regex, $str) === 1) {
    echo 'Matches!';
}

You can also do it without using regular expressions:

$str = str_replace(',', '', $str);
if (ctype_digit($str)) {
    echo 'Matches!';
}

If you care about the format then something like this would work:

$regex = '/^[0-9]+(?:,[0-9]+)*$/';
if (preg_match($regex, $str) === 1) {
    echo 'Matches!';
}

Answer 2

Just for fun with no regex:

var_dump(
    !array_diff($a = explode(',', $str), array_map('intval', $a))
);

Answer 3

You can use this regex:

'/^\d+(?:,\d+)*$/'

Code:

$re = '/^\d+(?:,\d+)*$/';
$str = '2323,321,329,34938,23123,54545,123123,312312'; 

if ( preg_match($re, $str) )
    echo "correct format";
else
    echo "incorrect format";