For in loop doesn't go over every item of object

Question

I'm using Node.js with Express for a back-end server. I am sending in some data as a json and after parsing it I'm trying to iterate through the object so I can assign values. For a test I'm passing in an object that has 50 objects in it.

I've tried using for in loop with hasOwnProperty but it has never completed all of them.

for (i in req.body.deviceObject) {
    if (req.body.deviceObject.hasOwnProperty.call(req.body.deviceObject[i].dId, i)) {
      newVcsObject[i] = new PQ(
        'insert into VCS(ip_address, vcs_name, user_name, user_password, ID) values ($1, $2, $3, $4, $5)'
      );
      newVcsObject[i].values = [
        req.body.deviceObject[i].ipAddress,
        req.body.customerName,
        req.body.deviceObject[i].uName,
        req.body.deviceObject[i].uPassword,
        req.body.deviceObject[i].VCSID
      ];
      console.log(i);
      count += 1;
    }
}

edit: this is my data structure:
"deviceObject": {
        "1": {
            "rId": "e43aebb5-234f-4aa6-a666-90179df767bc",
            "e164": "449bc7cc-90fa-4b9e-b4c1-1223d825d545",
            "uName": "Server",
            "uPassword": "admin",
            "VCSID": "54191576-47ea-4055-8ea4-bc201dc54f6d",
            "ipAddress": "1.1.1.1",
            "dId": "b6178041-86cc-4959-9155-54ca419083e7"
        },
        //there are more in between, this is where it's stuck
        "35": {
            "rId": "dce82b00-fa1e-46b8-a3f6-1a5af45175de",
            "e164": "7cc8190b-c261-40f8-9f62-408f7e8b2450",
            "uName": "access point",
            "uPassword": "admin",
            "VCSID": "3e3e447c-b9fe-4997-ba54-225175b0a84b",
            "ipAddress": "1.1.1.1",
            "dId": "9c97d5a5-b26f-492e-ba5b-bdd33eb3cb30"
        }
        // goes all the way to 50

I always go through 35/50 of the input. I have double checked and the server is receiving all 50 of them without a problem, but it only iterates through the first 35.

Are you trying to loop over properties on the object? If so look at this https://stackoverflow.com/questions/8312459/iterate-through-object-properties — TemporaryFix, Aug 27 '19 at 13:47
Is something different about the 35th object? Try echoing out deviceObject that doesn't match the if-statement. — Gavin, Aug 27 '19 at 13:47
For loops typically have no reason to not iterate through all objects. Is the application hanging during iteration? Also your count +=1 is within an if statement, so it does not guarantee that the count will be incremented. Add another variable (totalcount) to increment outside the if statement within the for loop to check if all items were iterated. — GLJ, Aug 27 '19 at 13:48
@Programmatic not entirely what I'm trying to do, but close! — abeldattsun, Aug 27 '19 at 13:51
@Gavin it's all generated in the front end and they're all identical except the unique ID's — abeldattsun, Aug 27 '19 at 13:51
@GLJ The count only supposed to count every time the newVcsObject has been added so it is in the correct spot. — abeldattsun, Aug 27 '19 at 13:51
if looks strange - do not think you need hasOwnProperty here and is dId in all records ? I would ask ... .hasOwnProperty(i) in case probably... — Jan, Aug 27 '19 at 14:49
@Tom the reason dId is not pushed to the database here is because it is pushed into another table. I just use it to make sure that it is there. I can try to exclude hasOwnProperty and see if it works. — abeldattsun, Aug 27 '19 at 14:51
@Tom other then ES-lint complaining it actually does all 50 this way .Can you please explain why? — abeldattsun, Aug 27 '19 at 14:52
Try to compare object's content or put them here or to https://pastebin.com/ etc. — Jan, Aug 27 '19 at 15:01

Neel Rathod · Answer 1 · 2019-08-27T15:06:08.973

0

const deviceObject = {
  1: {
    rId: 'e43aebb5-234f-4aa6-a666-90179df767bc',
    e164: '449bc7cc-90fa-4b9e-b4c1-1223d825d545',
    uName: 'Server',
    uPassword: 'admin',
    VCSID: '54191576-47ea-4055-8ea4-bc201dc54f6d',
    ipAddress: '1.1.1.1',
    dId: 'b6178041-86cc-4959-9155-54ca419083e7',
  },
  35: {
    rId: 'dce82b00-fa1e-46b8-a3f6-1a5af45175de',
    e164: '7cc8190b-c261-40f8-9f62-408f7e8b2450',
    uName: 'access point',
    uPassword: 'admin',
    VCSID: '3e3e447c-b9fe-4997-ba54-225175b0a84b',
    ipAddress: '1.1.1.1',
    dId: '9c97d5a5-b26f-492e-ba5b-bdd33eb3cb30',
  },
};
const custName = 'dummy'; // req.body.customerName;
const array = [];

Object.keys(deviceObject).forEach((r) => {
  const text = 'insert into VCS(ip_address, vcs_name, user_name, user_password, ID) values ($1, $2, $3, $4, $5)';
  const vals = deviceObject[r];
  const values = [vals.ipAddress, custName, vals.uName, vals.uPassword, vals.VCSID];
  const obj = {
    text,
    values,
  };
  array.push(obj);
});

console.log(array);

edited Aug 27 '19 at 15:06

answered Aug 27 '19 at 13:54

Neel Rathod

2,013
12
28

You can't use .length on an object like that I thought. – abeldattsun Aug 27 '19 at 14:08
@abeldattsun You can't. The first `if` statement throws an error if the data is anything other than an array, which, of course, yours isn't. – IronFlare Aug 27 '19 at 14:19
I thought It's in array ( `[]` ) form – Neel Rathod Aug 27 '19 at 14:20
Paste your input data and the expected outcome – Neel Rathod Aug 27 '19 at 14:21
1

The data structure is included at the bottom of the code block in the question. – IronFlare Aug 27 '19 at 14:21
@abeldattsun What you want to do with those objects? You want to store in somewhere else ? make another object with values? push into another array? – Neel Rathod Aug 27 '19 at 14:30
@NeelRathod I'm trying to put it into a new object that holds arrays so I can push it into my postgres database – abeldattsun Aug 27 '19 at 14:41
@abeldattsun So your new object will like this `const obj = { array: [], array2: [] }` ? If yes then what you want to do with that `deviceObject ` – Neel Rathod Aug 27 '19 at 14:43
@abeldattsun Do you want to push `deviceObject ` into that array? – Neel Rathod Aug 27 '19 at 14:45
it's a specific kind of way I have to work with PG-promise. You can see it in the code I posted. I create a newVcsObject and the ith element will hold the values. – abeldattsun Aug 27 '19 at 14:45
@NeelRathod '1': ParameterizedQuery { text: "insert into VCS(ip_address, vcs_name, user_name, user_password, ID) values ($1, $2, $3, $4, $5)" values: ["1.1.1.1","dummy","Server","admin","54191576-47ea-4055-8ea4-bc201dc54f6d"] }, This is what I create with that – abeldattsun Aug 27 '19 at 14:47
@abeldattsun Please check the updated answer. Is that what you want? – Neel Rathod Aug 27 '19 at 15:02
@NeelRathod nope not at all. This would not work for my case. But thank you for your help! – abeldattsun Aug 27 '19 at 15:05
@abeldattsun I hope you got some help from this answer – Neel Rathod Aug 27 '19 at 15:10

score 0 · Answer 2 · answered Aug 27 '19 at 16:53

So this isn't quite an answer, but I'm hoping this will aid in your debugging.

If your for loop has terminated, than that means it has successfully iterated through every object. If you are wondering why a new VcsObject was not correctly parsed, than it appears that the if statement did not succeed. Try using an else statement with a log to see if any failure occurred in you if statement so all control logic is accounted.

for (i in req.body.deviceObject) {
    if (req.body.deviceObject.hasOwnProperty.call(req.body.deviceObject[i].dId, i)) {
      newVcsObject[i] = new PQ(
        'insert into VCS(ip_address, vcs_name, user_name, user_password, ID) values ($1, $2, $3, $4, $5)'
      );
      newVcsObject[i].values = [
        req.body.deviceObject[i].ipAddress,
        req.body.customerName,
        req.body.deviceObject[i].uName,
        req.body.deviceObject[i].uPassword,
        req.body.deviceObject[i].VCSID
      ];
      console.log(i);
      count += 1;
    } else {
        // Log when the if-statement fails to execute
        console.log("Warning! If statement failed on iteration " + i)
    }
}

If your for loop has never terminated and is hung up, than that means you have some function that never returned. I'm not sure if this is your case, but then you'll need to either make several log statements to see at which point it failed or know which function may have never returned.

for (i in req.body.deviceObject) {
    console.log("Iteration: " + i)
    console.log("checking hasOwnProperty")
    if (req.body.deviceObject.hasOwnProperty.call(req.body.deviceObject[i].dId, i)) {
      console.log("Assigning a new PQ object")
      newVcsObject[i] = new PQ(
        'insert into VCS(ip_address, vcs_name, user_name, user_password, ID) values ($1, $2, $3, $4, $5)'
      );
      console.log("Assigning newVcsObject values")
      newVcsObject[i].values = [
        req.body.deviceObject[i].ipAddress,
        req.body.customerName,
        req.body.deviceObject[i].uName,
        req.body.deviceObject[i].uPassword,
        req.body.deviceObject[i].VCSID
      ];
      console.log(i);
      count += 1;
    } else {
        // Log when the if-statement fails to execute
        console.log("Warning! If statement failed on iteration " + i)
    }
}

Thanks! that's a good idea for debugging! The issue came from using hasownproperty. It stopped after a while. Not sure why. I disabled it and after testing it, it seems to be fixed — abeldattsun, Aug 27 '19 at 19:00
No problem! For debugging, start which big chunks of logic and slowly become more granular as you pinpoint the problem. As in my example, first I checked to see whether or not the if statement was executing. After that, I decided to check even further by adding the print statement after each line of execution to see if the results returned. The next step after that would be to begin diving within each called function to ensure no unknown side effects took place. — GLJ, Aug 27 '19 at 20:17
Also @abeldattsun Since the actual code that is breaking is not provided, I suggest placing the faltering code within your OP or closing this question as resolved. — GLJ, Aug 27 '19 at 20:59
the code that breaks is right there. That is where the fault is. I just removed the hasOwnProperty and that fixed the issue — abeldattsun, Aug 28 '19 at 12:12

For in loop doesn't go over every item of object

2 Answers2