Javascript "pre set" a variable?

Question

I'm trying to declare a variable whose value is another variable that isn't set at that time.

var add = 1 + three;
var three = 3;
document.getElementById('thediv').innerHTML = add;
//results in "NaN"

http://jsfiddle.net/seSMx/1/

Is there a way to do this using Jquery/Javascript?

Answer 1

You could turn add into a function,

http://jsfiddle.net/seSMx/3/

function add() {
   return 1 + (three || 0);
}

var three = 3;
document.getElementById('thediv').innerHTML = add();

Although, this would be very hard to follow in my opinion. I would take it a step farther and make three an argument to add

function add(three) {
   return 1 + (three || 0);
}

document.getElementById('thediv').innerHTML = add(3);

Answer 2

is this what are you going for?

var add = "1 + three";
var three = 3;
document.getElementById('thediv').innerHTML = eval(add);