In JavaScript there aren't operators defined that work on arrays, however, you can imitate their results:

Operations

List concatenation (+)

This is very simple as there is the Array#concat() method

a = [1, 2]
b = [3]

c = a + b

in JavaScript is equal to

const a = [1, 2];
const b = [3];

const c = a.concat(b);

console.log(c);

You could define a function that concatenates any amount of elements as:

const add = (...items) => [].concat(...items);

console.log("[1, 2] + [3]:", add([1, 2], [3]));
console.log("[1] + [2] + 3:", add([1], [2], 3));
console.log("[1, 2] + 3:", add([1, 2], 3));
console.log("1 + 2 + 3:", add(1, 2, 3));

List Repetition (*)

There is no native way to repeat an array in JavaScript. You can apply a loop and repeatedly call add, however an easier way might be to use Array.from. The first argument it takes is an array-like which can be used to define the size of the create {length: neededSize} and the second argument it takes is a function that will determine the contents of this array.

This is a simple implementation:

const mul = (arr, times) => 
  Array.from({length: times*arr.length}, (_,i) => arr[i%arr.length]);

console.log("[] * 3:", mul([], 3));
console.log("[1] * 3:", mul([1], 3));
console.log("[1, 2] * 3:", mul([1, 2], 3));
console.log("[1, 2, 3] * 3:", mul([1, 2, 3], 3));

Module that handles operations fluently

For the sake of it, here is a small module that makes the operations into a fluent interface and eagerly evaluates each operations:

const add = (...items) => 
  [].concat(...items);
const mul = (arr, times) => 
  Array.from({length: times*arr.length}, (_,i) => arr[i%arr.length]);

const arrayMath = arr => ({
  add: (...items) => arrayMath(add(arr, ...items)),
  mul: num => arrayMath(mul(arr, num)),
  result: () => arr
})

const res1 = arrayMath([])
    .add([1, 2])
    .add([3])
    .mul(2)
  .result();

const res2 = arrayMath([])
    .add(1, 2)
    .add([3])
    .mul(2)
  .result();

const res3 = arrayMath([])
    .add(1, [2])
    .add([3])
    .mul(2)
  .result();


const res4 = arrayMath([1])
    .mul(2)
    .add(2)
    .mul(3)
  .result();


console.log(res1);
console.log(res2);
console.log(res3);
console.log(res4);

Since when you simply multiply a number to an array, it will parse all the contents in array to integer to perform the operation, but while parsing it also considers the comma that separates the elements in the array, so ultimately the parse gives you a NaN(Not a Number).

So you have to do it manually by a for loop(or any loop):

var arr = [0,0];

 function myFunction() {
  let x;

  for(x=0;x<3;x++){
  arr.push(1)
 }

Change the variables according to your wish later.