I have a wordpress site with titles, and if the title has more than 50 characters I need to add an ellipsis (...) at the end of the title and stop the title at 50 characters. Be
echo (strlen(the_title())>50) ? (substr(the_title(), 0, 50) . "...") : the_title());
This is a ternary operator. What it basically says is if the result from the_title() is more than 50 characters, then echo the first 50 characters and then the string .... Otherwise, just echo the result from the_title().
You can read more about substr here: http://php.net/manual/en/function.substr.php
You can find info on the ternary operator here: http://php.net/manual/en/language.operators.comparison.php