js how does sort work code example

Example 1: javascript sort array strings alphabetically

//sort array alphabetically
objArray.sort(function(a, b) {
   return a.localeCompare(b);
});

Example 2: javascript order by string array

users.sort((a, b) => a.firstname.localeCompare(b.firstname))

Example 3: sort arrays according to first array js

itemsArray.sort(function(a, b){  
  return sortingArr.indexOf(a) - sortingArr.indexOf(b);
});