Based on javascript-natural-sort by Jim Palmer, JavaScript Natural Multisort adds support for "naturally" sorting arrays of objects by a property and also for sorting an array in descending order. All ...

The sort() method of {{jsxref("Array")}} instances sorts the elements of an array in place and returns the reference to the same array, now sorted. The default sort order is ascending, built upon ...

Each line is an object, and both lines together would be part of an array. Names in the name and value pairs include firstname and lastname, while the value pairs would be the actual appearing names, ...