How to solved that problem

Question

Function exercise
//In this exercise you are given an object called’ mathHelpers’ within mathHelpers, create a method called ‘double’ this method should take one parameter, a number, and it should return that number multiple by two.
JavaScript language

Answer 1

What language?

Answer 2

In certain languages, double will be a reserved word and you wouldn't be able to have a method with that name.

Answer 3

What language should this be in?