In JavaScript doing a simple shipping and handling calculation

Question

I am having trouble with a simple JavaScript calculation. My document is supposed to add $1.50 to an order if it is $25 or less, or add 10% of the order if it is more then $

Answer 1

Using parseFloat will help you:

var price = parseFloat(window.prompt("What is the purchase price?", 0))
var shipping = parseFloat(calculateShipping(price));
var total = price +shipping;
function calculateShipping(price){
if (price <= 25){
 return 1.5;
}
else{
 return price * 10 / 100
}
}
window.alert("Your total is $" + total + ".");

See it working at: http://jsfiddle.net/e8U6W/

Also, a little-known put more performant way of doing this would be simply to -0:

var price =window.prompt("What is the purchase price?", 0) - 0;

(See: Is Subtracting Zero some sort of JavaScript performance trick?)

Be sure to comment this, though as its not as obvious to those reading your code as parseFloat