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I want to make a custom Array object that recieves a number as index, and depending on the value of the index, it would return a computed value.

For example:

>>> var MyArray(2); >>> MyArray[2]; 4 >>> MyArray.2; 4

I know that for the showed example, I'm better of with a function, but I want to know if I can override the properties/index lookup for some things that are conceptualy arrays, but could need some computation.

I'm aware that x.1 == x[1], so what I need is to make a property in javascript.

I mean, make x.variable = x.myPropery(), so everytime that I get the value of x.variable, I recieve the return of x.myPorperty().

Is this even possible?

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variable[property] is the same as dot notation so you are doing MyArray.2, which is a variable, not a method that gets evaluated. You can't really do what you want without a method that either changes the property when it is assigned, or a method that computes the right value when you pull it out.

And no, you cannot override [], its simply dot notation, its not really an index that you can override

Re: your comment, Absolutely, you can do 

var x = new Array(); x[1] = function () { alert('x') }; var myFunction = x[1]; x[1](); // alerts "x" myFunction(); // alerts "x" alert(x[1]); // alerts "function () { alert('x') };" alert(myFunction); // alerts "function () { alert('x') };"
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I am aware of x[1] == x.1. Is there a way to make x.i == x.myProperty()?
I've since addressed that in the post, remember, you can declare and pass functions around and you can call them and get their results, but you cannot call a function without ()
I guess I've not explained myself correctly. I know that functions can be asigned, but can a property like Python's, .NET's be done, instead of Java's getters and setters?
You want a C# style getter like: int MyProperty get { return computed_value; }; ? If so, no you cant do that
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Currently Javascript Getters and Setters are possible only on

  • Firefox
  • Safari 3+
  • Opera 9.5+

Internet Explorer (in any of it versions) is lacking in this regard.

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