Sort array descending in Javascript

// ascending and discending for number
const arr1 = [21, 2100, 2, 35000];
const arr2 = [21, 2100, 2, 35000];

let ascN = arr1.sort((f, s) => f - s);
let dscN = arr2.sort((f, s) => s - f);

// ascending and discending for string
const arr3 = ['21', '2100', '2', '35000'];
const arr4 = ['21', '2100', '2', '35000'];

let ascS = arr3.sort((f, s) => f.length - s.length);
let dscS = arr4.sort((f, s) => s.length - f.length);

//used arraow functions
const years = [1970, 1999, 1951, 1982, 1963, 2011, 2018, 1922]
const sortYears = arr =>{
  arr.sort((a,b)=>{return b-a})
  return arr
}
console.log(sortYears(years))
// Should print [ 2018, 2011, 1999, 1982, 1970, 1963, 1951, 1922 ]