Group an array of objects in AngularJS

Question

Based on an array looking like this:

var members = [
  {name: "john", team: 1},
  {name: "kevin", team: 1},
  {name: "rob", team: 2},
  {name: "matt", team: 2},
  {name: "clint", team: 3},
  {name: "will", team: 3}
];

I need to create an unordered list for each team.

Can it be done directly with ngRepeat and a filter maybe?

Or is it easier to reorganize the array into an array of teams with a list of members?

var teams = [
  {id: 1, members: ["john", "kevin"]},
  {id: 2, members: ["rob", "matt"]},
  {id: 3, members: ["clint", "will"]}
]

The nested ngRepeat would be easy to implement, but how do I go from the first array to this one in a simple / clever manner?

Note: The array doesn't come from the database but from an html table. So it's just a flat list of members.

function MyController() {
  this.members = [
    {name: "john", team: 1},
    {name: "kevin", team: 1},
    {name: "rob", team: 2},
    {name: "matt", team: 2},
    {name: "clint", team: 3},
    {name: "will", team: 3}
  ];
}

angular.module('app', []);
angular.module('app')
    .controller('MyController', MyController);

<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.6.3/angular.min.js"></script>
<div ng-app="app">
  <div ng-controller="MyController as ctrl">
    <ul>
      <li ng-repeat="member in ctrl.members">{{ member.name }} - {{ member.team }}</li>
    </ul>
  </div>
</div>

this link will help you too..http://stackoverflow.com/questions/14800862/how-can-i-group-data-with-an-angular-filter — Muhammad Ramzan, Apr 06 '17 at 06:37

Mihai Alexandru-Ionut · Accepted Answer · 2017-04-06T06:41:16.443

You have to group items. For this, I used reduce method in order to create a hash collection which looks like this:

{
  "1": [
    "john",
    "kevin"
  ],
  "2": [
    "rob",
    "matt"
  ],
   "3": [
     "clint",
      "will"
   ]
}

The reduce() method applies a function against an accumulator and each element in the array (from left to right) to reduce it to a single value.

The following step is to map this collection in an array. For this, you should use map method.

The map() method creates a new array with the results of calling a provided function on every element in this array.

var members = [
  {name: "john", team: 1},
  {name: "kevin", team: 1},
  {name: "rob", team: 2},
  {name: "matt", team: 2},
  {name: "clint", team: 3},
  {name: "will", team: 3}
];
var groups = members.reduce(function(obj,item){
    obj[item.team] = obj[item.team] || [];
    obj[item.team].push(item.name);
    return obj;
}, {});
var myArray = Object.keys(groups).map(function(key){
    return {team: key, name: groups[key]};
});
console.log(myArray);

I'll go with this answer over the filter one. This way I can simply pass the transformed array to a service. — gyc, Apr 06 '17 at 06:41

score 6 · Answer 2 · answered Apr 06 '17 at 06:53

Expanding over the @Alexandru-Ionut Mihai's answer, (just to experience how powerful a reduce function is).. here's a single reduce without having to map it again to achieve the same thing. :)

var members = [
  {name: "john", team: 1},
  {name: "kevin", team: 1},
  {name: "rob", team: 2},
  {name: "matt", team: 2},
  {name: "clint", team: 3},
  {name: "will", team: 3}
];
/*var teams = [
  {id: 1, members: ["john", "kevin"]},
  {id: 2, members: ["rob", "matt"]},
  {id: 3, members: ["clint", "will"]}
]*/
var group_to_values = members.reduce(function(arr, item){
    arr[item.team - 1] = arr[item.team - 1] || { id: item.team, members: []};
    arr[item.team - 1].members.push(item.name);
    return arr;
}, []);

console.log(group_to_values);

kaushlendras · Answer 3 · 2017-04-06T06:36:28.310

If you are using underscore.js, then you can use _.groupBy() method to group array of records on the basis of team.

function MyController() {
  this.members = [
    {name: "john", team: 1},
    {name: "kevin", team: 1},
    {name: "rob", team: 2},
    {name: "matt", team: 2},
    {name: "clint", team: 3},
    {name: "will", team: 3}
  ];

var grouped = _.groupBy(this.members, function(member) {
  return member.team;
});
}

score 2 · Answer 4 · answered Apr 06 '17 at 06:33

You can use a groupBy filter like this

<ul ng-repeat="(key, value) in members | orderBy: 'team' | groupBy:ourGrouper">
      <li>{{key}}
        <ul>
          <li ng-repeat="mem in value | orderBy: 'name'">
            {{mem.name}}
          </li>
        </ul>
      </li>
    </ul>

See this FIDDLE

score 1 · Answer 5 · answered Jan 17 '19 at 11:36

var members = [
  {name: "john", team: 1},
  {name: "kevin", team: 1},
  {name: "rob", team: 2},
  {name: "matt", team: 2},
  {name: "clint", team: 3},
  {name: "will", team: 3}
];
var groups = members.reduce(function(obj,item){
    obj[item.team] = obj[item.team] || [];
    obj[item.team].push(item.name);
    return obj;
}, {});
var myArray = Object.keys(groups).map(function(key){
    return {team: key, name: groups[key]};
});
console.log(myArray);

Group an array of objects in AngularJS

5 Answers5

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