JavaScript básico: asignación del valor de una variable a otra

In this challenge I suppose that the last answer is a = b, after assigning the value 7 to the variable a and matching both variables, but in my case it does not give me the answer as well corrected. Here is my response code:
// Configuración
var a;
a = 7;
var b;
b = 7;
a = b;
// Cambia solo el código debajo de esta línea

The instructions are to assign the contents of a to b. Instead, you have assigned the contents of b to a. The tests are specifically looking for you to make assign a to b You have not made the assignment.

OK, thank you very much.

I am going to suggest a new test that says:

You should not try to directly assign the value 7 to variable b.

or something like the following in Spanish:

No debe intentar asignar directamente el valor 7 a la variable b.