"JavaScript exercises" function

(1) When passing a value of a primitive type to a parameter, the passed value is copied to a local variable (that is, an element in the arguments object). This means that the parameter is actually a local variable of the function.
(2) When passing a reference type to a parameter, the value in memory is copied to a local variable, so the change of the local variable will be reflected outside of the function.

"JavaScript exercises" function