how does sort work in javascript code example

Example 1: javascript string array sort alphabetically

var items = ['réservé', 'premier', 'communiqué', 'café', 'adieu', 'éclair'];
items.sort((a, b) =>
   a.localeCompare(b)//using String.prototype.localCompare()
);

Example 2: javascript sort array strings alphabetically

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

Example 3: how the sort function works javascript

const unsorted = ['d', 'd', 'h', 'r', 'v', 'z', 'f', 'c', 'g'];
const sorted = unsorted.sort();

console.log(sorted);
//["c", "d", "d", "f", "g", "h", "r", "v", "z"]


const unsortedNums = [45, 56, 3, 3, 4, 6, 7, 45, 1];
const sortedNums = unsortedNums.sort((a, b) => {
	return a - b;
});

console.log(sortedNums);
//[1, 3, 3, 4, 6, 7, 45, 45, 56]