old_contents: ebayTechnicalInterview.js
  
new_contents: Ebay Technical Interview. Senior Front End Engineer Role
  
  15 min Intro
  15 min on algorithm
  20 min on Javascript concepts
    - apply()
    - bind()
    - closure
    - what are self envoked function? pros/cons
    function anon(){
      convert(arr)
    }();
    - Ajax
      HTTP Get/Post
    - difference between class / id
    - what is the Event loop
    - how to access data attribute
      <div data-type='core'>
      </div>
    - what is the DOM ?
    - how to use querySelectorAll
    - what is arguments
    - what is function expression
    - what is declaration
  
    - ES6 syntax
      let / var
  
  Algorithm question:
  
  Write a function that will take this input array below, and and will output the result array
  
  input = [
      {
          itemId: 111111,
          title: 'Item-1',
          sellerName: 'seller-1',
          category: 'Electronics, Fitness'
      },
      {
          itemId: 222222,
          title: 'Item-2',
          sellerName: 'seller-2',
          category: 'Cars'
      },
      {
          itemId: 333333,
          title: 'Item-3',
          sellerName: 'seller-3',
          category: 'Electronics'
      },
      {
          itemId: 444444,
          title: 'Item-4',
          sellerName: 'seller-4',
          category: 'Cars , Bikes'
      }
      
  ]
  
  function convert(input){
  
  }
  
  
  
  //output - Group the items into Categories
  result =
  {
      Electronics: [
          {
              itemId: 111111,
              title: 'Item-1',
              sellerName: 'seller-1' 
          },
          {
              itemId: 333333,
              title: 'Item-3',
              sellerName: 'seller-3'
          }
      ],
      Cars: [
          {
              itemId: 222222,
              title: 'Item-2',
              sellerName: 'seller-2'
          },
          {
              itemId: 444444,
              title: 'Item-4',
              sellerName: 'seller-4'
          }
      ],
      Bikes: [
          {
              itemId: 444444,
              title: 'Item-4',
              sellerName: 'seller-4'
          }
      ],
  
      Fitness: [
          {
              itemId: 111111,
              title: 'Item-1',
              sellerName: 'seller-1'
          }
      ]
  }
  
  
  
  
  
subject: add desc