Object-Oriented JavaScript

Exercises

1. Write a function that converts a hexadecimal color, for example blue "#0000FF", into its RGB representation "rgb(0, 0, 255)". Name your function getRGB() and test it with this code:

   	>>> var a = getRGB("#00FF00"); 
   	>>> a; 

   "rgb(0, 255, 0)"

2. What does each of these lines print in the console?

   	>>> parseInt(1e1)
   	>>> parseInt('1e1')
   	>>> parseFloat('1e1')
   	>>> isFinite(0/10)
   	>>> isFinite(20/0)
   	>>> isNaN(parseInt(NaN));

3. What does this following code alert()?

   	var a = 1;
   	function f() {
   	  var a = 2;
   	  function n() {
   	    alert(a);
   	  }
   	  n();
   	}
   	f(); 

4. All these examples alert "Boo!". Can you explain why?

   4.1.

   	   var f = alert;
   	   eval('f("Boo!")');

   4.2.

   	   var e;
   	   var f = alert;
   	   eval('e=f')('Boo!'); 

   4.3.

   	   (
   	    function(){
     	      return alert;
   	    }
   	  )()('Boo!');