Question

So the following won’t work:

var Foo = {
    array1 : ['apples', 'oranges', 'grapes'],
    arrayLength : array1.length // error
}

Is there any way I can access Foo.array1‘s length within the object?

Answer 1

You’ll need to do it like this:

var Foo = {};
Foo['array1'] = ['apples', 'oranges', 'grapes'];
Foo['arrayLength'] = Foo['array1'].length;

Or like this (much cleaner IMHO):

var Foo = function() {
   var a = ['apples', 'oranges', 'grapes'];
   return {'array1': a, 'arrayLength':a.length};
}();

Another alternative:

function Foo(array) {
   this.array1 = array;
   this.arrayLength = array.length;
   //other stuff...
}

var f = new Foo(['apples', 'oranges', 'grapes']);

But really, this doesn’t make much sense to me, you’re already storing the array, why do you need to cache the length property?`