Question: I've heard a lot of talk that enabling bitcode decreases the binary size of an app downloaded from the app store onto iOS 9. I haven't been able to find any resources on whether or not bitcode decreases the binary size on previous iOS versions.

Does enabling bitcode decrease the binary size on iOS 7 or iOS 8?

**EDIT**
According to this [thread](https://forums.developer.apple.com/thread/19743) App Slicing and Bitcode are two separate components. This would make sense considering the documentation for [App Thinning](https://developer.apple.com/library/tvos/documentation/IDEs/Conceptual/AppDistributionGuide/AppThinning/AppThinning.html) splits them into different sections. Is there any official word from Apple on iOS requirements for Bitcode?

Answer: 
Here's another alternative approach. If your goal in looking for an equivalent of `use` in javascript is to write cleaner code, you might want to take a look at `window.variablename`. Variables at the global scope in javascript are implicitly properties of the window object. So for example, you could write:

```
var window.tax = 10;
var totalPrice = function (quantity, price){  //no need for 'use' or similar
    return (price * quantity) * (window.tax + 1.0);  //tax is usable here :(
};

```

This makes it explicitly clear to someone reading the code, that `tax` referenced in the function is the `tax` that's part of the global scope (namely `window.tax`).
First of all: JS is not PHP nor C++ and wont ever be.

`use()` is not for JS. You have lots of possible examples to do what you need, it'a pretty flexible language. Except those in previous answers, I'd like to share one more example:

```
var tax = 'improper';

var priceFactory = function(tax) { 
    // private `tax` variable for this scope
    var tax = tax;

    // or a nightmare to check it
    // var tax = 'number' ==  typeof tax && tax || function() { throw "No tax given"; }();

    return function(quantity, price) {
        return (price * quantity) * (1 + tax / 100);
    }
};

var price = new priceFactory(10); // 10%

var totalPrice = price(1, 100)

```