Group Javascript Array Of Objects By Id

What I want to achieve is to group objects together inside an array if the first two digits of the IDs matches. So given the below array of objects, I want to convert this ORIGINA

Solution 1:

You can use reduce() to return array and one object for grouping.

var data = [{"id":"0100","name":"name 1","message":"Lorem blah blah 1"},{"id":"0101","name":"","message":"Lorem blah blah 1.1"},{"id":"0200","name":"name 2","message":"Lorem blah blah 2"},{"id":"0201","name":"","message":"Lorem blah blah 2.1"},{"id":"0202","name":"","message":"Lorem blah blah 2.2"},{"id":"0300","name":"name 3","message":"Lorem blah blah 3"},{"id":"0301","name":"","message":"Lorem blah blah 3.1"},{"id":"0302","name":"","message":"Lorem blah blah 3.2"},{"id":"0303","name":"","message":"Lorem blah blah 3.3"},{"id":"0304","name":"","message":"Lorem blah blah 3.4"}];

var o = {}
var result = data.reduce(function(r, el) {
  var e = el.id.slice(0, 2);
  if (!o[e]) {
    o[e] = {
      id: el.id,
      name: el.name,
      message: []
    }
    r.push(o[e]);
  }
  o[e].message.push(el.message);
  return r;
}, [])

console.log(result)

Solution 2:

You could check for double zeroes and add the new group to the result set.

var data = [{ "id": "0100", "name": "name 1", "message": "Lorem blah blah 1" }, { "id": "0101", "name": "", "message": "Lorem blah blah 1.1" }, { "id": "0200", "name": "name 2", "message": "Lorem blah blah 2" }, { "id": "0201", "name": "", "message": "Lorem blah blah 2.1" }, { "id": "0202", "name": "", "message": "Lorem blah blah 2.2" }, { "id": "0300", "name": "name 3", "message": "Lorem blah blah 3" }, { "id": "0301", "name": "", "message": "Lorem blah blah 3.1" }, { "id": "0302", "name": "", "message": "Lorem blah blah 3.2" }, { "id": "0303", "name": "", "message": "Lorem blah blah 3.3" }, { "id": "0304", "name": "", "message": "Lorem blah blah 3.4" }],
    grouped = [];

data.forEach(function (a) {
    var key = a.id.slice(0, 2);
    if (a.id === key + '00') {
        this[key] = { id: a.id, name: a.name, message: [] };
        grouped.push(this[key]);
    }
    this[key].message.push(a.message);
}, Object.create(null));

console.log(grouped);

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