Basically I want to call myList[i] and get the same value for i = 1, 2, 3, 4 then a second value for 5, 6, 7, 8 and so on. I don't really want to copy-paste the value for 1 into 2, 3, 4.
You can use an array of objects
const arr = [...Array(4).fill({ value: 1 }), ...Array(4).fill({ value: 3 })];
console.log(arr[0].value);
console.log(arr[2].value);
console.log(arr[4].value);
console.log(arr[6].value);
arr[0].value = 2;
console.log(arr[0].value);
console.log(arr[2].value);
console.log(arr[4].value);
console.log(arr[6].value);Each element is a reference to the same object.
That's not possible with an array of primitives.
You can try using this -
myList[Math.floor((i-1)/4)]
where i = 1, 2, 3, 4 ...
But if i starts from 0, then
myList[Math.floor(i/4)]
Adjust the +/- 1 according to your requirements.
Where 4 is the block size to which you need to divide the array with.