title: Iterate through nested json array in angular controller and get unique values
body: <p>I need to iterate through nested json array which looks like that</p>
  
  <pre><code>[
    {
      "title": "EPAM",
      "technologies": [
          "PHP",
          ".net",
          "Java",
          "Mobile",
          "Objective-C",
          "Python",
          "Ruby"
      ],
      "location": "Belarus",
      "city": "Minsk" 
    },
    {
      "title": "Parallels",
      "technologies": [
          "PHP",
          "Java",
          "C++",
          "iOS Development",
          "C#",
          "Ember.js"
      ],
      "location": "Russia",
      "city": "Moscow" 
    }
  ]
  </code></pre>
  
  <p>What I want is to iterate through list of technologies in each company and then return a list of unique values. I failed, however, to access a single company in company arrays in the controller. It looks like this so far</p>
  
  <pre><code>var app = angular.module('app', []);
  
  app.controller('CompaniesController', ['$scope', '$http', 
    function($scope, $http) {
      $http.get('json/companies.json').success(function(data) {
          $scope.companies = data; // get data from json
  
          $scope.techStack = []
  
          $scope.companies = data.query(function(companies) {
              console.log(companies); //I expected to see data here
          });
      });
  
    }
  ]); 
  </code></pre>
  
  <p>Apparently I'm doing something wrong.</p>