Question

Here is an example:

            //    0     1       2      3       4
 var people = ['jack','jill','nancy','tom','cartman'];
 var order  = [3,1,4,0,2];

 // somehow sort people array to the order specified in the order array

          //  3      1       4        0      2
 people == ['tom','jill','cartman','jack','nancy'];

I have used .sort with a function before, but am still at a loss on this one.

UPDATE

after seeing some answers, I can’t believe this was not obvious to me. So as there are many ways to do this, winner will be determined by jsperf.

(also I am upvoting everyone with a working answer)

The RACE! http://jsperf.com/array-sorted-to-order-array3

Answer 1

order is an array of indicies. So just iterate through that, pulling out the values you want in the order spcified, making a new array.

var people = ['jack','jill','nancy','tom','cartman'];
var order  = [3,1,4,0,2];

var sorted = [];
for (var i = 0; i < order.length; i++) {
  var desiredIndex = order[i];
  sorted.push(people[desiredIndex]);
}

console.log(sorted);
// ["tom", "jill", "cartman", "jack", "nancy"]

Sometimes sorting isn’t “sorting”. Sometimes you just need to make a new thing by pulling data from your other things.