title: How to convert a string containing a hexadecimal integer
body: <p>I have a string for example containing 1000 i need to store it in a variable called x(for eg)
  so the whole thing is that i need to store a string as an hexadecimal base integer 
  so that if i add 3 (for example)</p>
  
  <pre><code>1000+3=1003
  1003+3=1006
  1006+3=1009
  1009+3=100C
  100C+3=100F
  100F+3=1012
  </code></pre>