Determine if a given string contains a given substring.
As i mentioned before the second parameter can be a string or an array of strings. In case it is a string the method returns true or false accordingly by searching in a case-sensitive manner. In case we pass an array of strings then the method returns true as long as it has at least one match no matter how many strings the $needles array contains. So in our third example the method returned true because there was 1 match while for in fourth example returned false because of 0 matches.