Question

I have an array which contains the following items:

var jobName = getNextJobName();
var Details = getNextJobDetails();
var item = {
          Name: jobName,
          Details: Details
        };
array.push(item);

I want to extract all the unique names (from the Name field).
(in order to create a new object which groups all the details for a specific job).

Could you please show me an efficient way to do this?

Answer 1

You mean have a list of those objects, and you want to extract all the unique values?

Here’s a pretty efficient way, storing the values as keys of a new object called uniq and the value being an array of the ‘Details’ element.

var arr = [ { Name: 'Alex', Details: 'Foo' }, { Name: 'Igor', Details: 'None' }, { Name: 'Alex', Details: 'Boo' } ];
var uniq = {}; // contains all the unique names
for(var i=0; i<arr.length; i++) {
  var el = arr[i].Name;
  if(!uniq[el]) uniq[el] = []; // start the array
  uniq[el].push(arr[i].Details);
}

http://jsfiddle.net/lmatteis/8LWMH/4/