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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?

borisdiakur
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    node; `root === global; // true` – jAndy Feb 05 '14 at 13:33
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    the outcome of `true` just tells us, that both names are referencing the same "object reference". – jAndy Feb 05 '14 at 13:43
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    @Lego but reference equality is a stronger result than deep equality... – OrangeDog Feb 05 '14 at 13:43
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    As you might not know, ECMAscripts objects are somewhat created in a black-hole (some ppl call it HEAP too) to say so. Even if you go like `var myobj = { };`, you will only receive a *reference* to a newly created object in ECMA-space, not the "object itself". Just for clarification. – jAndy Feb 05 '14 at 13:45

1 Answers1

15

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.

OrangeDog
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