[Javascript] __Index metamethod

[Nixola]

Does Javascript have metatables and/or metamethods, like Lua? If it doesn't, how can I achieve a rasult similar to __index?

[Roland_Yonaba]

Hi,
Well I do not think Javascript have an __index feature.
Though, the closest feature, IMHO, is the prototype feature.

[Inny]

The answer is it depends on what you're using it for.

If it's to simulate a class inheritance scheme, you use the function.prototype.member syntax and copying between objects.

If it's to simulate python's getattr/setattr, then no, Javascript doesn't have that kind of feature yet but the next ECMA standard is supposed to have one (get and set functions).

[Nixola]

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If it's to simulate python's getattr/setattr, then no, Javascript doesn't have that kind of feature yet but the next ECMA standard is supposed to have one (get and set functions).

I don't know Python, so I don't know what you're talking about... I want to set a default table value instead of "undefined", I only have one table and no objects, so I don't have to inherit anything; it's almost exactly like the following:

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var t = ['NULL', 'Mark', 'Jack'];
n = {USERCOUNT};  //I don't know if this syntax is common or if it's relative to the forum I'm editing, anyway that gets a number equal to the number of users
for (i = 1; i <=n; i++) {
document.write(t[i]+"<br />");
}

If the Usercount increases and I don't update the table (I can't get it automatically) I get:

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Mark
Jack
undefined

but I'd prefer to set something else instead of undefined...

[Inny]

I think the closest approximation is the Firefox extentions to javascript, one of which is __noSuchMethod__. However, being both javascript and firefox, and not lua or love, it's probably way off topic for this forum. You might want to search around on StackOverflow for a while to see what answers you can find.

[Nixola]

it's probably way off topic for this forum

That's why I posted in "General" and not in Support
Anyway, if it's only Firefox that can help me I think that "undefined" instead of the username will be ok. Thanks, anyway