title: Checking if a String is a number using switch
body: <p>I have to make a program which tells if a <code>String</code> <strong>that I type in my keyboard</strong> is a number, by using a <code>switch</code>. I know how to do it with try and catch, but I don't know how to do it with <code>switch</code>. </p>
  
  <p>Any tips?</p>