JavaScript for…in vs for

Question

Do you think there is a big difference in for...in and for loops? What kind of \"for\" do you prefer to use and why?

Let\'s say we have an array of associative array

Answer 1

With for (var i in myArray) you can loop over objects too, i will contain the key name and you can access the property via myArray[i]. Additionaly, any methods you will have added to the object will be included in the loop, too, i.e., if you use any external framework like jQuery or prototype, or if you add methods to object prototypes directly, at one point i will point to those methods.