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What is the root object in Node.js

Posted by: admin November 30, 2017 Leave a comment

Questions:

You may know the global object in Node.js:

{Object} The global namespace object.

In browsers, the top-level scope
is the global scope. That means that in browsers if you’re in the
global scope var something will define a global variable. In Node this
is different. The top-level scope is not the global scope; var
something inside a Node module will be local to that module.

Now I stumbled over the root object which seems to be documented nowhere.

Though it seems that I can use root the same way as global:

test1.js

foo = 'bar'; // foo is defined in the global scope (no var in front of foo)

test2.js

require('./test1.js');
console.log(root.foo);

In the shell:

$ node test2.js
bar

When I inspect global and root in the shell they look the same. Try:

$ node
> global
...
> root
...

So it seems that root is the same as global. But why the redundancy? Why is root not documented? Is it deprecated?

Answers:

It is exactly the same as global.

There are a few undocumented properties like this. They date from early days of node but were left in to maintain backwards-compatibility and there is no pressing need to remove them.

You shouldn’t use them in any new code, as they could be removed at any future time.