Demo of $.each and $.map

$.each-$.map.js

// jQuery source outlines differences

const items = [1, 2, 3, 4, 5];

// MAP

// $.map() returns a new array
const array = $.map(items, function (item, index) { // item first then index
    console.log(item);

    // Multiply the item by 2 and return so as to push on to the internal stack
    return item * 2;
});

console.log('Return from $.map(): %o ', array);

// EACH

// $.each() returns the same array passed in
const array = $.each(items, function (index, item) { // index first then item
    console.log(item);

    // Break the loop
    if (item === 3) {
        return false;
    }
});

console.log('Return from $.each(): %o ', array);

// NOTE: $.map() can't be "broken" unlike $.each() as false in $.map() is considered a value whereas in $.each(), the callback is a predicate of true or false