I'm having a little trouble with the JS delete() function.
Straight from Chrome Inspector:
> x = [{name: 'hello'}, {name: 'world'}]
> [Object, Object]
> delete x[0]
> true
> $.each (x, function (i, o) {console.log(o.name);})
> TypeError: Cannot read property 'name' of undefined
> x
> [undefined × 1, Object]
Do you have any idea why this is happening? It's causing me issues with that each
Deleting x[0] is not the same as slicing that entry out of the array. Element 1 is still at x[1] in other words, so x[0] is undefined.
To properly remove objects from the array, you should use the splice method.
x = [{name: 'hello'}, {name: 'world'}];
x.splice(0,1);
The delete() method on the Array data structure is a little misleading. When you do the following:
var a = ['one', 'two', 'three'];
delete a[0];
delete() does something similar to assigning the array element to undefined. Note that after using delete(), the array is not shifted and the length remains the same:
a.length -> 3
a[0] -> undefined
So in essence, delete() creates a sparse array and does not alter the length property nor remove the element. To completely remove the element, you want to do the following:
a.splice(0,1)
This will both remove the element and alter the array's length property. So now:
a.length -> 2
See the the splice method for details on method arguments.
delete() because I'm deleting items in an each().
quantity field Now I update that list, by adding more elements. For every existent element in Limbo, I update the quantity, and for elements that don't exist, I add them with quantity = 1. I iterate the elements I want to add, and if I find it in Limbo, I increase the quantity and delete the item. When iterating is done, all I have is elements that need to be added, so I once iterate.