Second, the distinction of where the inheritance of a thing comes from does not change the functionality of the thing. It helps in understanding some of its behaviors. If a type of animal is a classified as carnivorous we know that it eats meat, but that does not mean it can be substituted for other meat eating animals. Some carnivores hunt and some do not.
The first two points should convey the understanding that within this post saying everything is an object we are saying this for classification purposes and to understand their behaviors in a way that makes sense. An array is one type of object and the functionality of a number is not the same as an array.
Object.prototype.isobject = true;
When new objects are created.
The new objects inherit the methods, properties, etc of which they came from.
document.write(a.isobject); /* true */