JS Best Practices
Keep functions focused and validate values at the boundary. Returning data makes a calculation easier to reuse and test.
Where to run this
This example uses the JavaScript console playground. Select Run to execute it; the example does not run on this lesson page.
A practical example
function bookingTotal(price, count) {
if (!Number.isFinite(price)) throw new TypeError("Invalid price");
return price * count;
}
console.log(bookingTotal(6, 2));
What happens
The function returns 12 for a valid numeric price.