Question

Definitive JavaScript by David Flanagan makes a distinction between Objects and Primitives.

He defines the primitives as Number, String, Boolean, Null, and Undefined, as does the standard.

However, would it be more accurate to define a primitive, as subset of object, i.e. to call them Primitive Objects.

Because they have their own methods and are complex entities.

Actual Question

Would Primitive Object be more accurate than Object when defining String, Boolean, and Number?

Answer 1

Objects and primitives are distinct:

typeof 42 === "number"             
typeof new Number(42) === "object"
new Number(42) !== 42

However, when necessary, primitives are automatically wrapped by temporary objects, which can be automatically converted back into primitives:

(42).toString() === "42"
new Number(42) == 42
new Number(42) + 1 === 43

Especially in the context of the Java and C# programming languages, this sort of behavior is called autoboxing. As wrapper objects have some confusing characteristics, for example:

Boolean(new Boolean(false)) === true

it is good practice to avoid intentionally storing them in variables and instead use primitives whenever possible.