RMMZ [Javascript] Shifting only select elements of array?

[ct_bolt]

Another one for ya guys... kind of has me stumped...

Shifting only select elements of array while keeping the rest of the array as is though.

Example:

const a = ["A", 4, "B", "C", "D", 1, 2, 3];

How would I shift only the numbers while keeping the rest of the array as is.

So the first shift should end up like this:

["A", 3, "B", "C", "D", 4, 1, 2]

Second shift like this:

["A", 2, "B", "C", "D", 3, 4, 1]

Thanks again for any/all help advice.

 

[Nolonar]

You can do this:

a = a.map(element => typeof element === "number" ? shift(element) : element);

This will give you a new array where only numbers have been shifted.
As for the shift method, you probably want this:

const shift = n => n - 1 || 4;

Obviously, n has to be greater than 0, otherwise you'll get negative numbers.

For more control you can also define shift this way:

const shift = (n, max) => n - 1 || max;

 

[Masked]

I think you'll need to give a bit more detail on the logic of what you're trying to achieve with this one, from what you've said the only thing it can think of is swapping the elements on the array, like this:

const a = [1, "a", 3, "b", "c", 4];

let aux = a[2];
a[2] = a[5];
a[5] = aux;

Aside from that, is there any particular reason to have strings and numbers mixed on the same array? It's usually not very good to have elements that behave differently on a collection. If you can split this into two arrays, one for strings and another for integers, then it's a lot easier to do (just pop and unshift).