Javascript group by object properties

Question

I have an array of objects below

var inventory = [
    { Name: "KIT001", SerialNo: "K111", Status: "Out For Cleaning", NewStatus: "Cleaned" },
    { Name: "KIT001", SerialNo: "K112", Status: "Out For Cleaning", NewStatus: "Cleaned" },
    { Name: "KIT001", SerialNo: "K113", Status: "Out For Cleaning", NewStatus: "Cleaned" },
    { Name: "KIT001", SerialNo: "K132", Status: "Out For Cleaning", NewStatus: "Need Cleaning" },
    { Name: "KIT001", SerialNo: "K134", Status: "Out For Cleaning", NewStatus: "Need Cleaning" },
];

I would like to do a group by "Out For Cleaning" and "Cleaned" in such a way that the end result would return multiple arrays like below:

var arr1 = [
    { Name: "KIT001", SerialNo: "K111", Status: "Out For Cleaning", NewStatus: "Cleaned" },
    { Name: "KIT001", SerialNo: "K112", Status: "Out For Cleaning", NewStatus: "Cleaned" },
    { Name: "KIT001", SerialNo: "K113", Status: "Out For Cleaning", NewStatus: "Cleaned" },
];

var arr2 = [
    { Name: "KIT001", SerialNo: "K132", Status: "Out For Cleaning", NewStatus: "Need Cleaning" },
    { Name: "KIT001", SerialNo: "K134", Status: "Out For Cleaning", NewStatus: "Need Cleaning" },
];

UPDATE

I need to do a group by STATUS first and then NEW_STATUS. Note, that these arrays will be dynamic.

var STATUS = ["Out For Cleaning", "Out For Repair"];
var NEW_STATUS = ["Cleaned", "Repaired"];

This is what I came up with however, it only groups by the STATUS property.

for (var i = 0; i < STATUS.length; i++) {
          var arr1 = inventory.filter(function (el) {
               return el.Status == STATUS[i];
          });

          if(arr1.length > 0)
               console.log('Final Array: ', arr1)              
}

Possible duplicate of [Javascript: Split array of objects into seperate arrays with dynamic names depending on property value](https://stackoverflow.com/questions/54008878/javascript-split-array-of-objects-into-seperate-arrays-with-dynamic-names-depen) — David Lemon, Jan 11 '19 at 13:21

score 2 · Answer 1 · answered Oct 06 '15 at 00:06

2

One way would be to filter the array:

var arr1 = status.filter(function(el) {
    return el.NewStatus == "Cleaned";
});

var arr2 = status.filter(function(el) {
    return el.NewStatus == "Need Cleaning";
});

answered Oct 06 '15 at 00:06

bgse

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Your answer helped me get started. – mihai6744 Oct 06 '15 at 22:55

score 0 · Answer 2 · answered Nov 06 '15 at 16:00

This is what I would do:

function GroupBy(array){
  var fields = Array.prototype.slice.call(arguments, 1);
  var field = fields.shift();

  if(field){

    var groupedArray = [];
    for(var i in array){
      var index = array[i][field];
      groupedArray[index] = groupedArray[index] || [];
      groupedArray[index].push(array[i]);
    }

    for(var i in groupedArray)
      groupedArray[i] = GroupBy.bind(null, groupedArray[i]).apply(null, fields);

    return groupedArray;
  }

  return array;
}

Then use it like this. Group the records by fields:

var groupedArray = GroupBy(yourArray, "STATUS", "NEW_STATUS");

Then get records by the specified fields:

var list = groupedArray["Out For Cleaning"]["Need Cleaning"];

score 0 · Answer 3 · answered Dec 15 '18 at 11:53

for (var i = 0; i < STATUS.length; i++) {

  var arr1 = inventory.filter(function(el) {
      return el.NewStatus == NEW_STATUS[i-1];
      console.log(el.NewStatus);
  });

  document.getElementById("grey").innerHTML =JSON.stringify(arr1);

  var arr2 = inventory.filter(function(el) {
      return el.NewStatus == NEW_STATUS[i];
  });

  document.getElementById("blue").innerHTML =JSON.stringify(arr2);

}

Javascript group by object properties

3 Answers3