title: check in a string php
body: <p>I have a string and it can contain values like this
  $string = '1,2,3,4,5';
  I wanna put a check that will see if the string contains 4 or 5
  if it contains 4 or 5 then I want to echo success
  otherwise if it contains 9 or 10 I wanna echo fail</p>
  
  <p>I know there is a n in_array function but not sure how to use it
  thanks</p>