One final legal statement in JavaScript is the empty statement. It
      looks like this:
      
      Executing the empty statement obviously has no effect and
      performs no action. You might think that there would be little
      reason to ever use such a statement, but it turns out that the
      empty statement is occasionally useful when you want to create a
      loop that has an empty body. For example:
      
// initialize an array a
for(i=0; i < a.length; a[i++] = 0) ; 
 
      To make your code clear, it can be useful to comment your empty
      statements as such:
      
for(i=0; i < a.length; a[i++] = 0) /* empty */ ;