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up vote 4 down vote favorite

This question already has an answer here:

I'm confused with Node.js function arguments object.

Suppose i have following code:

function x() {
  return arguments;
}

console.log(x(1, 2, 3));

In chrome developer tools it returns as an Array:

[1, 2, 3]

But i got different result in node.js:

{ '0': 1, '1': 2, '2': 3 }

How come?

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marked as duplicate by Moses, Trott, A.V, Rachel Gallen, Denis Tulskiy Mar 30 '13 at 6:19

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.
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3 Answers

up vote 5 down vote accepted

arguments is a magic variable that isn't actually an Array. It behaves like an Array, but it doesn't have all the functions that an Array has.

Other objects like this are NodeList for example.

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1  
Ok @Frits van Campen. I got it. I run this to check it's type: console.log(Object.prototype.toString.call(x())); Both return same result: [object Arguments] –  user1725316 Mar 29 '13 at 15:10
    
Cool, I didn't know you could do that =) –  Halcyon Mar 29 '13 at 15:13
    
very funny frits. LoL –  user1725316 Mar 29 '13 at 15:21
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up vote 3 down vote

You see different representation of an object which isn't array in Chrome neither in Node and in javascript at all.

If you want an array out of it, you do that:

var args = Array.prototype.slice.call(arguments, 0);
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up vote 0 down vote

console.log is not part of javascript, and not part of v8. Which is why both chrome and node.js have there own implementations of console.log. They have simular apis, but not the same. The documentation for node's console.log is here: http://nodejs.org/api/stdio.html

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