Question About Order of Setting Export

Node
1

In the Node Module System portion of the “Complete Node.js Course”, Mosh talks about the order of setting export variables.

For example, we can have something like this:

function hello(name) {
    console.log("Hello", name);
}
var name = "kaushik";
module.exports = hello;
module.exports.name = name;

However, we cannot set it in this order:

module.exports.name = name;
module.exports = hello;

I am not really understanding what is going on in the background, since in the first example, we are setting a variable to be a function and then setting a property of that function to be a variable (?!?)

And I am not sure why that is any better/worse in the example when the order is switched.

I would really appreciate any help to understand what is going on in the background!

2

module.exports starts off as an empty object, {}. So by doing this…

module.exports.name = name;

you’ve added a name property to that object.

But then when you do this…

module.exports = hello;

you’ve completely replaced that object with the hello function i.e. module.exports now refers to the function, not the original object.

But if you flip that around and do this first…

module.exports = hello;

you’ve still replaced that object with the function, but then this…

module.exports.name = name;

adds a name property to the function, as you suspected. So you end up exporting both the function and the name. Though it’s a bit weird! You could also export them separately, like this…

module.exports.hello = hello;
module.exports.name = name;

in which case the exported object will have a hello property which refers to the function and a separate name property which refers to the name.

1 Like
3

That makes a little more sense; thanks!