Check if a string contains a set of characters at the end of a string

Question

I have a simple problem, but has become a troublesome problem:

$variable="This is some text***";

if (strpos($variable,'*') !== false) {
   echo 'found *';
} else {
   echo 'not found *';
}

But it will find a * in the text no matter how many *s there are.

I want to make it only can be found by searching specified star, *** (three stars) instead only * (one star).

Answer 1

To make it even more strict matching, that you only want it to match a string that contains *** at the end of the string you can use regex, so,

if (preg_match('~[^*]\*{3}$~', $str)) {
    print "Valid";
}

What this says is when a string has 3 stars at the end and there are no asterisks before those 3 stars then it will be true. Change the 3 to a 2 or 1 or whatever number of stars you want to match.

[^*] means that there can be a character but it cannot be a star that is followed by 3 stars. \*{3} means it will match 3 stars. The backslash is to escape asterisk for the pattern match and 3 is the number of total stars.

It could be a function like this:

function starMatch($str, $count) {
    return (bool)preg_match('~[^*]\*{'.$count.'}$~', $str);
}

And called like this:

starMatch($str, 1);  // matches *
starMatch($str, 2);  // matches **
starMatch($str, 3);  // matches ***