what sorting algorithmn does javascript sort use code example

Example 1: 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]

Example 2: sorting in js

var arr = [23, 34343, 1, 5, 90, 9]

//using forEach
var sortedArr = [];
arr.forEach(x => {
    if (sortedArr.length == 0)
        sortedArr.push(x)
    else {
        if (sortedArr[0] > x) sortedArr.unshift(x)
        else if (sortedArr[sortedArr.length - 1] < x) sortedArr.push(x)
        else sortedArr.splice(sortedArr.filter(y => y < x).length, 0, x)
    }
})
console.log(sortedArr);


// using sort method
console.log(arr.sort((a,b)=>{
    return a-b;
}));