How do I sort an array of objects based on the ordering of another array?

Question

I have a list of objects:

[ { id: 4, name:\'alex\' }, { id: 3, name:\'jess\' }, { id: 9, name:\'...\' }, { id: 1, name:\'abc\' } ]

I have a

Answer 1

A little something like this:

var data = [ { id: 4, name:'alex' }, { id: 3, name:'jess' }, { id: 9, name:'...' }, { id: 1, name:'abc' } ],
    order = [ 3, 1, 9, 4],    
    sorted = [],    
    items = {},
    i;

for (i = 0; i < data.length; i++)
   items[data[i].id] = data[i];

for (i = 0; i < order.length; i++)
   sorted.push(items[order[i]]);

The idea is to put the items from data into an object using the ids as property names - that way you can retrieve the item with a given id without without having to search through the array. (Otherwise you'd have to use a nested loop, or the Array.indexOf() function inside a single loop which is effectively going to be a nested loop as far as performance.)

This assumes that no two elements in data have the same id property.