Unable to understand what is missing in my solution

JavaScript
21

like what you quoted as
if(object[id][prop] == "")

22

Ah, yeah, you are not checking the function argument prop is an empty string there (it’s not undefined because you’ve deleted it, sorry), I assume it’s undefined because of something else you’ve done in the code.

updateRecords(collection, 2548, "tracks", "")
  • object is collection
  • id is 2548
  • prop is "tracks" 
if(object[id][prop] == ""){
    delete object[id][prop]
    console.log("this will be deleted"+ object[id][prop])
}

So

if(object[id][prop] == "") {

Is

if (collection[2548].tracks == "") {

Which is

if ( ['Let It Rock', 'You Give Love a Bad Name'] == "") {

And that isn’t true, so that code block doesn’t run, so nothing gets deleted from there

1 Like
23

I’m pretty sure that object[id][prop] is not an argument of the function

24

I m totally lost on this. I do not how to break it more down as I do not want to cheat but understand what I am missing or doing wrong, how to check each statement and find out if it is what they are asking me.

here I am trying to do line by line but why do I have undefined? I tried with [prop] too but it didn’t work and was undefined.

Screenshot 2021-04-12 at 23.21.02

25

The object with the id 5439 does not have a tracks or artist property.

var collection = {
  5439: {
    albumTitle: 'ABBA Gold'
  }
};

const prop = 'artist';

console.log(collection['5439'].tracks); // undefined
console.log(collection['5439'][prop]); // undefined
26

If value is an empty string, delete the given prop property from the album.

You have a function updateRecords(object, id, prop, value).

So for the function call updateCollection(collection, 2548, "tracks", ""), what is value?

27

Please bear with me as I sound really stupid to ask this for a long time and I could see the solution to cheat but I really want to understanding my mistake and lack of knowledge. I haven’t been able to give it time much since a week but I want to restart the problem. the following is my first statement

// Only change code below this line
function updateRecords(object, id, prop, value) {
  //If prop isn't tracks and value isn't an empty string, update or set that album's prop to value.
if(object[id].hasOwnProperty(prop) && object[id][prop] != ''){
  return object[id][value]
}
  return object;
}

updateRecords(collection, 5439, 'artist', 'ABBA');

I want to find out why is it wrong or what I am doing wrong.

28

have you tried answering this question?

1 Like
29

I didn’t get that but now I did. thanks. @DanCouper the value is empty string (’")

30

how do you check for that?

31

(collection[id].tracks == "")

I was going over the whole thread and wondering isn’t that the way to check if the prop has a value which is empty string e.g in the above code example I am asking
if collection object has a given id which has prop called tracks and if it is equal to "" (empty string) ?

32

but isn’t the function parameter that can have a value of empty string?

33

oh u mean like if (collection[2548].tracks == value) ?

34

still no

do you understand what the challenge asks you to do?
you beed to change the object, and how you change it depends on the values of the function parameters

you never check what are the values of the function parameters

35

let me correct my answer to above if (collection[id].tracks == value) ?

as for ur question if I understand what is being asked, so there r four things being asked.

  • If prop isn’t tracks and value isn’t an empty string, update or set that album’s prop to value .
  • If prop is tracks but the album doesn’t have a tracks property, create an empty array and add value to it.
  • If prop is tracks and value isn’t an empty string, add value to the end of the album’s existing tracks array.
  • If value is an empty string, delete the given prop property from the album.
36

and how are you checking the values of prop and value?

37

Right, I’m going to write a skeleton here of the thing you’re trying to do. You are having huge difficulty here seeing how the instructions relate to the code you’re supposed to be writing, but the way they are written actually translates directly to code. Maybe this will help. Can you just fill in what goes in the head of each of the if blocks. I’ve given each one a number, then the thing to fill in is numbered below: can you convert from the description of the condition in English to the condition in JS?

function updateRecords (object, id, prop, value) {
  if (/* fill this in with 1 */) {
    // Ignore this for now
  } else if (/* fill this in with 2 */) {
    // Ignore this for now
  } else if (/* fill this in with 3 */) {
    // Ignore this for now
  } else if (/* fill this in with 4 */) {
    // Ignore this for now
  }

  // Your function must always return the entire object.
  return object;
}
  1. If prop isn’t “tracks” and value isn’t an empty string, update or set that album’s prop to value.
  2. If prop is “tracks” but the album doesn’t have a “tracks” property, create an empty array and add value to it.
  3. If prop is “tracks” and value isn’t an empty string, add value to the end of the album’s existing “tracks” array.
  4. If value is an empty string, delete the given prop property from the album
38 
function updateRecords (object, id, prop, value) {
  if (!object[id].hasOwnProperty(prop) && object[id][prop] !== value) {
    //if object with given id does not have the given property  AND object 
   //with given id's prop is not equal to value
  } else if (object[id].hasOwnProperty(prop) && object[id].hasOwnProperty("tracks") {
    // if object with id has a property (prop) AND object with given id has //own property named tracks
  } else if (object[id][prop] && object[id][prop] !== value) {
    // if object with given id has prop AND object with given id and prop is //not equal to the value
  } else if (object[id][prop] == value) {
    // if object with given id and prop equal to value
  }

  // Your function must always return the entire object.
  return object;
}

This is what I would write, is it wrong?

Edit: I have made comment under my condition to show what I have done

39

well, you are not checking the value of prop anywhere
and you never check if value is an empty string or not

1 Like
40

I don’t see how the code you wrote checks for those 4 cases. Can you explain how you think that code works?