Possible Duplicate:
Self-references in object literal declarations
How do I do the following:
var object = {
alpha: 'one',
beta: **alpha's value**
}
without splitting the object creation into two parts?
-
Hmm.. well that stinks. I was trying to add enum types to my object like var object = { CURVETYPE: {DIRECT: 0, ROAD: 1}, travel: this.CURVETYPE.DIRECT }, but I can see this is going to ruin my nice namespace now...Nick– Nick2010-08-02 21:53:14 +00:00Commented Aug 2, 2010 at 21:53
Add a comment
|
4 Answers
You can't, as noted. The closest equivalent is:
var object = new (function()
{
this.alpha = 'one';
this.beta = this.alpha;
})();
This uses a singleton instance created from an anonymous function. You can also declare private fields with var.
Comments
You can't, object literal syntax just doesn't support this, you'll have to create a variable first then use it for both, like this:
var value = 'one';
var object = {
alpha: value,
beta: value
};
Or...something entirely different, but you can't reference alpha when doing beta, because neither property has been created yet, not until the object statement runs as a whole is either accessible.
2 Comments
Nick
.. I'm getting "o is undefined"
Nick Craver
You cannot do that with {} object creation.
Comments
Another idea for a way to create that object, without cluttering the scope with any new variables:
var lit = function(shared) {
return {
alpha: shared.v1,
beta: shared.v2,
gamma: "three",
delta: shared.v1
};
}(
{
v1: "one",
v2: "two",
}
);
One of those statements you're not sure how to indent....
