How does "var n=Number(3);" work?

Question

I used var n=Number(3);by mistake (I should have usedvar n=new Number(3);), but I got n=3. As Number() is an object constructor, who can explain this?

Answer 1

An object constructor is also a function.

Number^{(MDN doc)} as a function can be used to convert to a primitive type number.

> Number(3)
  3
> Number("3")
  3
> Number("A")
  NaN
> Number("2e2")
  200
> Number("0xff")
  255
> ["1", "2", "3"].map(Number)
  [1, 2, 3]