Sort an array of objects by multiple criteria and possible undefined values

Question

I'm trying to sort my javascript array of objects

ownerName     dogCode   dogName
Bob           5         Rex
John        
Alisha        3         Moon
Darren        4         Boss  
Josh
Cerq

I want it to be sort first by dogCode (just if exists or not, ignoring the number), than by ownerName, and finally by dogName, like this:

ownerName     dogCode   dogName
Alisha        3         Moon
Bob           5         Rex    
Darren        4         Boss 
Cerq
John        
Josh

I tried this:

data.sort(function (a, b) {
    if (a.dogCode < b.dogCode || !a.dogCode) return 1;
    if (a.dogCode > b.dogCode || !b.dogCode) return -1;
    if (a.ownerName < b.ownerName || !a.ownerName) return 1;
    if (a.ownerName > b.ownerName || !b.ownerName) return -1;
    if (a.dogName < b.dogName || !a.dogName) return 1;
    if (a.dogName > b.dogName || !b.dogName) return -1;
     return 0;
});

Aparenttely, It is sorting by dogCode correctly, but not by name/dogName. How can I do this?

EDIT: here is my json object:

{
  "data": [
    {
      "ownerName": "Bob",
      "dogCode": "5",
      "dogName": "Rex"
    },
    {
      "ownerName": "John"
    },
    {
      "ownerName": "Alisha",
      "dogCode": "3",
      "dogName": "Moon"
    },
    {
      "ownerName": "Darren",
      "dogCode": "4",
      "dogName": "Bos"
    },
    {
      "ownerName": "Josh"
    },
    {
      "ownerName": "Cerq"
    }
  ]
}

do you have zero vlaues for dogCode? do you have some data for testing? — Nina Scholz
– Nina Scholz, Commented Nov 13, 2020 at 17:41

BCDeWitt · Accepted Answer · 2020-11-13 18:23:00Z

It may not be the most efficient way, but I find the code below to be pretty understandable. Note that the sorts need applied in the opposite order from how you listed them.

const obj = {
  "data": [
    {
      "ownerName": "Bob",
      "dogCode": "5",
      "dogName": "Rex"
    },
    {
      "ownerName": "John"
    },
    {
      "ownerName": "Alisha",
      "dogCode": "3",
      "dogName": "Moon"
    },
    {
      "ownerName": "Darren",
      "dogCode": "4",
      "dogName": "Bos"
    },
    {
      "ownerName": "Josh"
    },
    {
      "ownerName": "Cerq"
    }
  ]
};

const byPropExists = prop => (a, b) => {
  if (a[prop] !== undefined && b[prop] === undefined) return -1;
  if (a[prop] === undefined && b[prop] !== undefined) return 1;
  return 0;
}
const byPropValue = prop => (a, b) => a[prop]?.localeCompare(b[prop])

// Note the reverse order of your sorts
console.log(obj.data
  .sort(byPropValue('dogName'))
  .sort(byPropValue('ownerName'))
  .sort(byPropExists('dogCode'))
);

Nina Scholz · Accepted Answer · 2020-11-13 18:10:50Z

0

You could take the delta of the check for undefined as sorting value and sort by delta of numbers or with String#localeCompare for strings.

const data = [{ ownerName: 'Bob', dogCode: 5, dogName: 'Rex' }, { ownerName: 'John' }, { ownerName: 'Alisha', dogCode: 3, dogName: 'Moon' }, { ownerName: 'Darren', dogCode: 4, dogName: 'Boss' }, { ownerName: 'Josh' }, { ownerName: 'Cerq' }];

data.sort((a, b) =>
    (a.dogCode === undefined) - (b.dogCode === undefined) ||
    (a.ownerName === undefined) - (b.ownerName === undefined) ||
    (a.dogName === undefined) - (b.dogName === undefined) ||

    (a.ownerName || '').localeCompare(b.ownerName || '') ||
    a.dogCode - b.dogCode ||
    (a.dogName || '').localeCompare(b.dogName || '')
);
   
console.log(data);

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

edited Nov 13, 2020 at 18:10

answered Nov 13, 2020 at 17:49

Nina Scholz

388k26 gold badges367 silver badges417 bronze badges

5 Comments

aseolin Over a year ago

Your code snippet has an error: "Uncaught ReferenceError: result is not defined"

aseolin Over a year ago

In your code, "Bob" is after "Darren", so this is not the expected result

Nina Scholz Over a year ago

please add some more data to show how dogCode should be sorted.

aseolin Over a year ago

You can ignore de dogCode value, it is just to know who has a dog.

Nina Scholz Over a year ago

you could play with your whole data set and move the less important sorting rules to the end of the function.

Collectives™ on Stack Overflow

Sort an array of objects by multiple criteria and possible undefined values

2 Answers 2

Comments

5 Comments

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

5 Comments

Related