underscorejs[Answered] RSS

• • Reply
  ssvikramuk

  Member

  229 Points

  662 Posts

  underscorejs

  Sep 01, 2016 06:27 PM|ssvikramuk|LINK

  Countby category based on userId using undersocrejs.

  Please refer the below script, its printing the value "Technology:2" & "Analytics:1".

  Expected answer: "Technology:1" & "Analytics:1" because both the 'Technology' objects are the same userId ie. 1

  arrayFlatten = [
        {
          area:"Digital",
          category:"Technology",
          userId:1,
          weightedAverage:10
        },
        {
          area:"Digital",
          category:"Technology",
          userId:1,
          weightedAverage:20
        },
        {
          area:"Digital",
          category:"Analytics",
          userId:2,
          weightedAverage:30
        }
  ]
  var types = _.groupBy(arrayFlatten, 'category');
  console.log(types);
  var result = {};
  _.each(types, function(val, key) {
    console.log(key+" "+val.length);
  });
  console.log(result);
  

  Thanks

• • Reply
  Nan Yu

  All-Star

  18815 Points

  3831 Posts

  Re: underscorejs

  Sep 02, 2016 06:40 AM|Nan Yu|LINK

  Hi ssvikramuk,

  If you group By "category" , you will get two groups , one group is "Technology" has two items , one group is "Analytics" has one item . For example :

  _.groupBy(['one', 'two', 'three'], 'length');
  
  result:
  => {3: ["one", "two"], 5: ["three"]}

  Try the code in   https://forums.meteor.com/t/underscorejs-countby-category/28790 

  And here is a code sample for how to get unique property .Click here for code sample .

  Best Regards,

  Nan Yu