Filter array of object with unique value from duplicate values

Question

var  Error-dictionary = [
   {
      code:599,
      MSG:'unknown' 
   },
   {
      code:404, 
      MSG:'not found'
   },
   {
      code:599, 
      MSG:'unknown'
   }
]

I want something like this:

[
  {
     code : 599,
     count:2,  
     MSG : 'unknown', 
     code :404,
     count:1,
     MSG : 'not found' 
  }
]

and this need to push into $scope.alerts as a MSG

Error code and MSG are dynamic

what do you do if your MSG is different for the same error code ? — dlght
– dlght, Commented Oct 12, 2015 at 14:43
iterate array and create new object. Please show what you tried ... this isn't a code writing service — charlietfl
– charlietfl, Commented Oct 12, 2015 at 14:47
you can count the number of appearences easily, but how do you deal with the different error codes ? take the most common or the first ? — dlght
– dlght, Commented Oct 12, 2015 at 14:55
Is the example output supposed to be an array of two objects? That's not a valid javascript object with two copies of the same property. — ryanyuyu
– ryanyuyu, Commented Oct 12, 2015 at 15:01

Marko · Accepted Answer · 2015-10-12 17:02:49Z

1

You can get the number of an specific property in a array of objects, by using underscore.js. Nice and easy!!!

<script src="http://underscorejs.org/underscore-min.js"></script>
<script>
  window.onload = function () {
    var dict = [
      {code: 599, MSG: 'unknown' },
      {code: 404, MSG: 'not found'},
      {code: 599, MSG: 'unknown'}
    ];

    var res = _.groupBy(dict, function (d) {
      return d.code;
    });

      var dictArr = []; 

        for(var key in res) {

            var code = key; 
            var value = res[key]; 
            var MSG = value[0].MSG; 
            var count = value.length; 
            dictArr.push({ code : code, MSG: MSG, count: count  }); 

        }; 

        console.log(dictArr); 


  };
</script>

edited Oct 12, 2015 at 17:02

answered Oct 12, 2015 at 14:52

Marko

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4 Comments

dlght Over a year ago

this does not result in what the OP is asking :]

charlietfl Over a year ago

have to know what codes exist and will iterate array for each code ... not very efficient or scaleable

Marko Over a year ago

You can't group by msg also. You just need to for-loop this one time to create the object he wants

Marko Over a year ago

Now does the result reflect exactly what he does ask. I was not aware he needed so much handholding.

charlietfl · Accepted Answer · 2015-10-12 15:19:52Z

0

Create a temp object that uses the error code and message as keys. Then map that temp object to output array

var tmp = {}, res =[];
data.forEach(function (item) {
    var tmpKey = item.code + item.MSG;
    if (!tmp.hasOwnProperty(tmpKey)) {
        tmp[tmpKey] = angular.copy(item);
        tmp[tmpKey].count = 0;
    }
    tmp[tmpKey].count++;
});

for( var key in tmp){
   res.push(tmp[key]; 
}
$scope.errors = res;
console.log($scope.errors);

edited Oct 12, 2015 at 15:19

answered Oct 12, 2015 at 15:13

charlietfl

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1 Comment

Marko Over a year ago

angular.copy(item); and $scope.errors = res; is angular?

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