Lodash sort collection based on external array

Question

I have an array with keys like so:

[\'asdf12\',\'39342aa\',\'12399\',\'129asg\',...] 

and a collection which has these keys in each object

Answer 1

Input:

var data1 = ['129asg', '39342aa'];
var data2 = [{
    guid: '39342aa',
    name: 'John'
}, {
    guid: '129asg',
    name: 'Mary'
}];

1. First create an index object, with _.reduce, like this

   var indexObject = _.reduce(data2, function(result, currentObject) {
       result[currentObject.guid] = currentObject;
       return result;
   }, {});
   

2. And then map the items of the first array with the objects from the indexObject, like this

   console.log(_.map(data1, function(currentGUID) {
       return indexObject[currentGUID]
   }));
   

Output

[ { guid: '129asg', name: 'Mary' },
  { guid: '39342aa', name: 'John' } ]

Note: This method will be very efficient if you want to sort so many objects, because it will reduce the linear look-up in the second array which would make the entire logic run in O(M * N) time complexity.