title: convert ASCII value to a character based on specific char in php
body: <p>I'd like to ask dumb question.
  How could I convert @48@49@50 based on @ char ?
  In PHP, understand that chr() function is used to convert a ASCII value to a character.
  48 is 0.
  49 is 1.
  And 50 is 2.
  May I know how to convert @48@49@50 as 012 and how to store 012 in one variable ?
  Eg- $num = 012</p>