Need help about operators in Javascript

Hi guys,
I’m building a calculator with javascript (for the front-end project) and I’ve been wondering how the computer sees operators, let me explain:

let a = 3 + 5; // a = 8; Right? And same for all other operators.

But I can not do let plus = +; I get an error, and let plus = "+"; makes it a string so I can’t use it for operations.

So they’re not Numbers neither Strings which makes me wondering what is the type of operators? (If they have one).
And basically I’m trying to refactor some repeated code into a function for (+, -, *, / operations)
but I can’t find a way to say

function operation(array, index, operator)
let result = array[index] operator array[index+1];
return result;

operation(this.array, 3, +);

It’s been driving me crazy a little bit, thanks for your help me understanding.

they are operators

the type is a property of data types, an operator gives instructions on how to operate on the data, but is not data itself

see for example