title: Grouping objects in an array by multiple keys
body: <p>Initially, I've this array:</p>
  
  <pre><code>[{
      "vendorid": 1,
      "vendorname": "Vendor1",
      "maxfilelimit": 2,
      "uploadfilename": "Voice1.xlsx"
  },
  {
      "vendorid": 1,
      "vendorname": "Vendor1",
      "maxfilelimit": 2,
      "uploadfilename": "Ven1_Voice.xlsx"
  },
  {
      "vendorid": 2,
      "vendorname": "Vendor2",
      "maxfilelimit": 2,
      "uploadfilename": "Voice2.xlsx"
  },
  {
      "vendorid": 2,
      "vendorname": "Vendor2",
      "maxfilelimit": 2,
      "uploadfilename": "Ven2_Voice.xlsx"
  }]
  </code></pre>
  
  <p>I want the file names in an array with no repetition of records. So, I expect the output similar to following:</p>
  
  <pre><code>[{
      "vendorid": 1,
      "vendorname": "Vendor1",
      "maxfilelimit": 2,
      "uploadfilename": ["Voice1.xlsx", "Ven1_Voice.xlsx"]
  }, {
      "vendorid": 2,
      "vendorname": "Vendor2",
      "maxfilelimit": 2,
      "uploadfilename": ["Voice2.xlsx", "Ven2_Voice.xlsx"]
  }]
  </code></pre>
  
  <p>I found some solutions like d3.js, alaSQL but not getting output as expected</p>