javascript- pushing an array of object into another failed

Question

I have an array of rooms of an asylum.

 var rooms = [
    {
      "id": 1001,
      "room": "room 1"
    },
    {
      "id": 1002,
      "room": "room 2"
    },
    {
      "id": 1003,
      "room": "room 3"
    },
    {
      "id": 1004,
      "room": "room 4"
    }
  ];

And I also have a list of patients of that asylum.

 var patients = [
    {
        "id": 10,
        "room": "room 1",
        "patient_name": "John"
    },
    {
        "id": 11,
        "room": "room 1",
        "member_name": "Jane"
    },
    {
        "id": 12,
        "room": "room 1",
        "member_name": "Joe"
    },
    {
        "id": 20,
        "room": "room 2",
        "patient_name": "Matt"
    },
    {
        "id": 30,
        "room": "room 3",
        "patient_name": "Alexa"
    }
  ];

Each patient belongs to a specific room. I wanna add those patients under their rooms and make a new array which looks like this:

  var asylum = [
    {
      "id": 1001,
      "room": "room 1",
      "patients": [
        {
          "id": 10,
          "room": "room 1",
          "patient_name": "John"
        },
        {
          "id": 11,
          "room": "room 1",
          "member_name": "Jane"
        },
        {
          "id": 12,
          "room": "room 1",
          "member_name": "Joe"
        }
      ]
    },
    {
      "id": 1002,
      "room": "room 2",
      "patients": [
        {
          "id": 20,
          "room": "room 2",
          "patient_name": "Matt"
        }
      ]
    },
    {
      "id": 1003,
      "room": "room 3",
      "patients": [
        {
          "id": 30,
          "room": "room 3",
          "patient_name": "Alexa"
        }
      ]
    },
    {
      "id": 1004,
      "room": "room 4",
      "patients": []
    }
  ]

That's my expected output but I'm not exactly getting that. This is the code I wrote to achieve the desired result.

for (var i = 0, len = rooms.length; i < len; i++) {
  for (var j = 0, len2 = patients.length; j < len2; j++) {
    if (rooms[i].room === patients[j].room) {
      rooms[i].members = patients[j];
    }
  }
}

I made a Fiddle. I have printed the array in console. Only one element is getting pushed.

The last added patient overwrites the previous patient. Perhaps use an array and push the patients to it. — Maximilian Peters
– Maximilian Peters, Commented Nov 10, 2017 at 11:33

Héctor Valls · Accepted Answer · 2017-11-10 11:32:54Z

1

You are changing the value of rooms[i].members each time you find a patient. Instead, you need to push the new patient into the array:

for (var i = 0; i < rooms.length; i++) {
  for (var j = 0; j < patients.length; j++) {
    if (rooms[i].room === patients[j].room) {
        if (!rooms[i].members) { //this is the first patient found for this room, so you need to initialize the array
            rooms[i].members = [];
        }
        rooms[i].members.push(patients[j]);
    }
  }
}

answered Nov 10, 2017 at 11:32

Héctor Valls

26.4k43 gold badges153 silver badges268 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Nina Scholz · Accepted Answer · 2017-11-10 11:36:11Z

You could use a hash table for the same rooms and a two loop approach by generating the asylum array and assigning the hash and the second loop for pushing the patients into the rooms.

var rooms = [{ id: 1001, room: "room 1" }, { id: 1002, room: "room 2" }, { id: 1003, room: "room 3" }, { id: 1004, room: "room 4" }],
    patients = [{ id: 10, room: "room 1", patient_name: "John" }, { id: 11, room: "room 1", member_name: "Jane" }, { id: 12, room: "room 1", member_name: "Joe" }, { id: 20, room: "room 2", patient_name: "Matt" }, { id: 30, room: "room 3", patient_name: "Alexa" }],
    hash = Object.create(null),
    asylum = rooms.map(function (o) {
        return hash[o.room] = { id: o.id, room: o.room, patients: [] };
    });

patients.forEach(function (o) {
    hash[o.room].patients.push(o);
});

console.log(asylum);

.as-console-wrapper { max-height: 100% !important; top: 0; }

Suren Srapyan · Accepted Answer · 2017-11-10 11:40:16Z

Iterate over the patients and for each patient check the room with the rooms. If you find, add to the found room

var rooms = [{"id": 1001, "room": "room 1"}, {"id": 1002, "room": "room 2"}, {"id": 1003, "room": "room 3"}, {"id": 1004, "room": "room 4"}];

var patients = [{"id": 10, "room": "room 1", "patient_name": "John"}, { "id": 11, "room": "room 1", "member_name": "Jane"}, {"id": 12, "room": "room 1", "member_name": "Joe"}, {"id": 20, "room": "room 2", "patient_name": "Matt"}, {"id": 30, "room": "room 3", "patient_name": "Alexa"}];
  
patients.forEach(patient => {
    var room = rooms.find(room => patient.room === room.room);
    
    if(room) {
         
       if(!room.patients) {
          room.patients = [];
       }
      
       room.patients.push(patient);
    }

 });
 
 console.log(rooms);

PhilMaGeo · Accepted Answer · 2017-11-10 11:59:41Z

Here is my script : beware you made a mistake using sometimes patient_name and sometimes member_name

    var asylum = [];


 var rooms = [
    {
      "id": 1001,
      "room": "room 1"
    },
    {
      "id": 1002,
      "room": "room 2"
    },
    {
      "id": 1003,
      "room": "room 3"
    },
    {
      "id": 1004,
      "room": "room 4"
    }
  ];

 var patients = [
    {
        "id": 10,
        "room": "room 1",
        "patient_name": "John"
    },
    {
        "id": 11,
        "room": "room 1",
        "patient_name": "Jane"
    },
    {
        "id": 12,
        "room": "room 1",
        "patient_name": "Joe"
    },
    {
        "id": 20,
        "room": "room 2",
        "patient_name": "Matt"
    },
    {
        "id": 30,
        "room": "room 3",
        "patient_name": "Alexa"
    }
  ];
  
  var asylum = [];
  
var aRoomWithPatients,apatient,rooma,roomb,name;
for (var i = 0; i < rooms.length; i++) {
   aRoomWithPatients = {};
   aRoomWithPatients.id = rooms[i].id;
   aRoomWithPatients.room = rooms[i].room;
   aRoomWithPatients.patients = [];
   asylum.push(aRoomWithPatients);
  for (var j = 0; j < patients.length;  j++) {
  rooma = rooms[i].room;
  roomb = patients[j].room;
  name = patients[j].patient_name;
    if (rooma === roomb) {
		apatient = {};
		apatient.id = patients[j].id;
		apatient.room = patients[j].room;
		apatient.patient_name = name;
        asylum[i].patients.push(apatient);
    }
  }
}
console.log(asylum);

Collectives™ on Stack Overflow

javascript- pushing an array of object into another failed

4 Answers 4

Comments

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

4 Answers 4

Comments

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related