title: How do I remove a some properties from an object in typescript?
body: <p>Say I create an object as follows:</p>
  
  <pre><code>formSummery: any = [];
  
  {
    "jobs" : [ {
      "job_id" : 10,
      "users" : [ {
        "user_id" : 11,
        "data_points" : [ {
          "efficiency" : "good",
          "form_id" : "2",
          "instrument_type" : "plug",
          "background_value" : "7",
          "surveyed_item_id" : "100",
          "duration" : 0,
          "start_time" : "2017-07-20T04:04:43.000Z",
          "datastream" : "GENERIC",
          "username" : "abc@gmail.com.com"
        }]
      } ]
    } ]
  }
  </code></pre>
  
  <p>What is the best way to remove the property datastream, username and start_time to end up with new formSummery as follows?</p>
  
  <pre><code>{
    "jobs" : [ {
      "job_id" : 10,
      "users" : [ {
        "user_id" : 11,
        "data_points" : [ {
          "efficiency" : "good",
          "form_id" : "2",
          "instrument_type" : "plug",
          "background_value" : "7",
          "surveyed_item_id" : "100",
          "duration" : 0
        }]
      } ]
    } ]
  }
  </code></pre>
  
  <p>Now, I have two same arrays formSummery and unstrdformSummery , and I want to delete some properties from second array (unstrdformSummery) and those properties still want in first array (formSummery):</p>
  
  <pre><code>formSummery = 
  { 
      "planned_activity":"Yes",
      "ingest_time":"2017-08-03T12:12:32.456Z",
      "arrival_time":"8",
      "device_id":"26e09c88237d5342",
      "user_name":"ABC","form_id":"1",
      "firmware_version":"2.2",
      "site_access_was_provided_as_expected":"Yes",
      "energy_manager":"Aaaa",
      "duration":0,
      "start_time":"2017-08-03T12:12:28.736Z",
      "datastream":"GENERIC",
      "addressing_percent_complete":"92",
      "password":"pwd",
      "template_name":"Daily Field Report",
      "user_id":11,
      "site_access_notes":"testing",
      "startup_percent_complete":"65",
      "energy_manager_ip":"0:0:0:0",
      "was_site_access_granted_on_time":"Yes",
      "departure_time":"9",
      "username":"abc@gmail.com"
  }
  
  
  unstrdformSummery =
  {
      "planned_activity":"Yes",
      "ingest_time":"2017-08-03T12:12:32.456Z",
      "arrival_time":"8",
      "device_id":"26e09c88237d5342",
      "user_name":"ABC","form_id":"1",
      "firmware_version":"2.2",
      "site_access_was_provided_as_expected":"Yes",
      "energy_manager":"Aaaa",
      "duration":0,
      "start_time":"2017-08-03T12:12:28.736Z",
      "datastream":"GENERIC",
      "addressing_percent_complete":"92",
      "password":"pwd",
      "template_name":"Daily Field Report",
      "user_id":11,
      "site_access_notes":"testing",
      "startup_percent_complete":"65",
      "energy_manager_ip":"0:0:0:0",
      "was_site_access_granted_on_time":"Yes",
      "departure_time":"9",
      "username":"abc@gmail.com"
  }
  </code></pre>