replace last seven characters of string

Question

I have a string and I want to replace the last 7 charators of the string with \"#\". For example I have \"MerryChristmasu87yujh7\" I want to replace \"87yujh7\" with seven \

Answer 1

Should be...

$match = substr($string, -7);

... without the final -1. But in fact, it's far better done with...

$result = substr($string, 0, -7) . str_repeat('#', 7);

... or, more generic:

$coverWith = function($string, $char, $number) {
  return substr($string, 0, -$number) . str_repeat($char, $number);
};