How do I check if a JavaScript parameter is a number?

Question

I\'m doing some trouble-shooting and want to add a check that a parameter to a function is a number. How do I do this?

Something like this...

function fn         


        

Answer 1

function fn(id){ 
  if((parseFloat(id) == parseInt(id)) && !isNaN(id)){
      return true;
  } else { 
      return false;
  } 
}