.size(target)

Returns the number of items contained in target. Target can provide the size using the can.size symbol.

If the target has a numeric length property that is greater than or equal to 0, that length will be returned.

canReflect.size([1,2,3]) //-> 3

If the target is isListLike, the values of the list will be counted.

If the target is a plain JS object, the number of enumerable properties will be returned.

canReflect.size({foo:"bar"}) //-> 1

If the target is anything else, undefined is returned.