I agree with you. the terminoloty is misleading.
the argument contains a reference to a object, u can change the content of the argument, but at end of the function the argument points to the same memory address. in C++ this is more clear, beacause u have the "&" reference operador, then u can pass the address of the argument itself, in this way, u can change the address the argument points.

then, in C++ u can assingn new values for dest and source within the function of the problem.

Thanks for the answers, talk about this things, improve the understading of the subject.

I guess you misunderstand the fact of the passage by reference you pass a reference to parameter, the address of a paramenter, not the address to object pointed, the parameter contain a address for object, but passage by reference pass a reference for a parameter, in this case you can change the paremeter itself.

google it:
"
The parameters, in a function call, are the function's arguments. JavaScript arguments are passed by value: The function only gets to know the values, not the argument's locations. If a function changes an argument's value, it does not change the parameter's original value.
"

Yes, it is the concept of pass by value, we can change the object in memory, but the parameter at the end of function pointers to the same memory address.
Otherwise, by reference, you could change the object pointed and the parameter itself.

It's a great Kata, I learned alot about JavaScript.

JS parameters are always passed by value, this increase the difficult of the problem, you have to discover a solution for this.

assign values to dest or source does not work within the function.

Wow! beautiful, this is so good!

Congratz, Very classy solution

nice!

this is so beautiful, like o poem.

Beautiful

Thank you for the answers, now it's clear.

I did not get the point, maybe because I 'm brazilian :) and my english is not so good,
What the relation between streets, guns, bullets and magazines? I did not understand.