Sort an array based on another array of integers

Let's say I have an array: [0,3,4,2,5,1].

What I want to do is sort an array such as:

["one", "two", "three", "four", "five", "six"]

So that the order corresponds to the first array.

This would be the output:

["one", "four", "five", "three", "six", "two"]

Is there an easy way to accomplish this?

Solution 1:

You can do something like this:

function getSorted(arr, sortArr) {
  var result = [];
  for (var i = 0; i < arr.length; i++) {
    console.log(sortArr[i], arr[i]);
    result[i] = arr[sortArr[i]];
  }
  return result;
}
var arr = ["one", "two", "three", "four", "five", "six"];
var sortArr = [0, 3, 4, 2, 5, 1];
alert(getSorted(arr, sortArr));

Note: this assumes the arrays you pass in are equivalent in size, you'd need to add some additional checks if this may not be the case.

Solution 2:

orderedArray= function(arr,order){
    return  order.map(function(itm){return arr[itm]});
}

var sequence= [0, 3, 4, 2, 5, 1],arr=["one","two","three","four","five","six"]

arr=new orderedArray(arr,sequence);

/*  returned value: (Array)
one,four,five,three,six,two
*/

//You can make the order an unindexed property of the array, // and call array.ordered()

Array.prototype.ordered= function(order){
    var arr= this;
    order=order || this.order;
    return order.map(function(itm){
        return arr[itm];
    });
}


var arr= ["one","two","three","four","five","six"],
sequence= [0, 3, 4, 2, 5, 1];

arr.order=sequence;

arr.ordered()

/*  returned value: (Array)
one,four,five,three,six,two
*/

Solution 3:

I was asked this on a phone interview. Then do it without creating another array, supposing the array is very large. I don't know if this is the answer since I wasn't able to do on the call (damn!), but here's what I came up with.

var my_obj_array = ['a', 'b', 'c', 'd'];
var my_indicies = [3, 1, 0, 2];
// desired result ['d', 'b', 'a', 'c']

var temp = {};
for (var i = 0; i < my_indicies.length; i++) {
    temp[i] = my_obj_array[i];  // preserve
    var j = my_indicies[i];
    if (j in temp) {
        my_obj_array[i] = temp[j];
        delete temp[j];
    } else {
        my_obj_array[i] = my_obj_array[j];
    }
}

http://jsfiddle.net/innerb/RENjW/