在PHP中修改逗号分隔列表中的字符串的最短方法

Question

If I want to modify a comma separated list like this:

$foo = "2, 4, 33, 25, 66"

to become

$foo = "'1-2', '1-4', '1-33', '1-25', '1-66'"

What would be the fastest and most efficient way to achieve that in PHP?

EDIT: I have tried this, but looking for a better way:

$foo = "2, 4, 33, 25, 66";
$bar = implode("', '1-",explode(",",$foo));
$foo = "'1-". $bar ."'";

Answer 1

$foo = "2, 4, 33, 25, 66";
echo preg_replace("/(\d+)(,?)/", "'1-$1'$2", $foo );

As requested by @roullie, here's a fast regex solution. In the regex, \d+ matches 1 or more digits. ,? matches 0 or 1 comma (the last item does not have a common so I must match on 0 or 1.