Turn groups into concat of arrays javascript

Question

I have managed to split an array into separate groups based on key value. What I want to achieve is to turn these groups which can be more or less into an array, so my groups become [[Regio__c],[Categorie__c]] instead of {Regio__c:[],Categorie__c:[]}. This with plain javascript no libraries.

I tried: return [key].concat.split; this returns undefined.

Below is my code in a snippet

var filter = [{
    "Id": "120",
    "arrayPicklist": "Categorie__c"
  }, {
    "Id": "121",
    "arrayPicklist": "Regio__c"
  },
  {
    "Id": "122",
    "arrayPicklist": "Categorie__c"
  }, {
    "Id": "123",
    "arrayPicklist": "Regio__c"
  },
  {
    "Id": "121",
    "arrayPicklist": "Regio__c"
  }
]


function splitArrayByValue(arr, key) {
  var split = {};
  for (var i = 0; i < arr.length; i++) {
    var p = arr[i][key];
    if (!split[p]) {
      split[p] = [];
    }
    split[p].push(arr[i])
  }
  return split;
}


var buckets2 = splitArrayByValue(filter, 'arrayPicklist');

console.log(buckets2);

Answer 1

You almost there, you need to get the values. An alternative is using the function Object.values

var filter = [{    "Id": "120",    "arrayPicklist": "Categorie__c"  }, {    "Id": "121",    "arrayPicklist": "Regio__c"  },  {    "Id": "122",    "arrayPicklist": "Categorie__c"  }, {    "Id": "123",    "arrayPicklist": "Regio__c"  },  {    "Id": "121",    "arrayPicklist": "Regio__c"  }]

function splitArrayByValue(arr, key) {
  var split = {};
  for (var i = 0; i < arr.length; i++) {
    var p = arr[i][key];
    if (!split[p]) {
      split[p] = [];
    }
    split[p].push(arr[i])
  }
  return Object.values(split);
}


var buckets2 = splitArrayByValue(filter, 'arrayPicklist');

console.log(buckets2);

You can use the function reduce to group and then the function Object.values to get the desired output.

var filter = [{"Id":"120","arrayPicklist":"Categorie__c"},{"Id":"121","arrayPicklist":"Regio__c"},{"Id":"122","arrayPicklist":"Categorie__c"},{"Id":"123","arrayPicklist":"Regio__c"},{"Id":"121","arrayPicklist":"Regio__c"}];

var result = Object.values(filter.reduce((a, {Id, arrayPicklist}) => {
  (a[arrayPicklist] || (a[arrayPicklist] = [])).push({Id, arrayPicklist});      
  return a;
}, {}));

console.log(result);

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Answer 2

Just return Object.values(split) instead of split in splitArrayByValue function.

var filter = [{"Id":"120","arrayPicklist":
"Categorie__c"},{"Id":"121","arrayPicklist":"Regio__c"},
{"Id":"122","arrayPicklist":"Categorie__c"},{"Id":"123","arrayPicklist":"Regio__c"},
{"Id":"121","arrayPicklist":"Regio__c"}]


function splitArrayByValue(arr, key) {
  var split = {};
  for (var i=0; i<arr.length; i++) {
    var p = arr[i][key];
    if (!split[p]) { split[p] = []; }
    split[p].push(arr[i])
  }
  return Object.values(split);//<---- just return Object.values(split) instead of split 
}


var buckets2 = splitArrayByValue(filter,'arrayPicklist');

console.log(buckets2);