How to sort an array of objects by multiple fields?

Viewed 337572

From this original question, how would I apply a sort on multiple fields?

Using this slightly adapted structure, how would I sort city (ascending) & then price (descending)?

var homes = [
    {"h_id":"3",
     "city":"Dallas",
     "state":"TX",
     "zip":"75201",
     "price":"162500"},
    {"h_id":"4",
     "city":"Bevery Hills",
     "state":"CA",
     "zip":"90210",
     "price":"319250"},
    {"h_id":"6",
     "city":"Dallas",
     "state":"TX",
     "zip":"75000",
     "price":"556699"},
    {"h_id":"5",
     "city":"New York",
     "state":"NY",
     "zip":"00010",
     "price":"962500"}
    ];

I liked the fact than an answer was given which provided a general approach. Where I plan to use this code, I will have to sort dates as well as other things. The ability to "prime" the object seemed handy, if not a little cumbersome.

I've tried to build this answer into a nice generic example, but I'm not having much luck.

37 Answers

This is a complete cheat but I think that it adds value to this question because it's basically a canned library function that you can use out-of-the box.

If your code has access to lodash or a lodash compatible library like underscore then you can use the _.sortBy method. The snippet below is copied directly from the lodash documentation.

The commented results in the examples looks like they return arrays of arrays but that's just showing the order and not the actual results which are an array of objects.

var users = [
  { 'user': 'fred',   'age': 48 },
  { 'user': 'barney', 'age': 36 },
  { 'user': 'fred',   'age': 40 },
  { 'user': 'barney', 'age': 34 }
];

_.sortBy(users, [function(o) { return o.user; }]);
 // => objects for [['barney', 36], ['barney', 34], ['fred', 48], ['fred', 40]]

_.sortBy(users, ['user', 'age']);
// => objects for [['barney', 34], ['barney', 36], ['fred', 40], ['fred', 48]]

A dynamic way to do that with MULTIPLE keys:

  • filter unique values from each col/key of sort
  • put in order or reverse it
  • add weights width zeropad for each object based on indexOf(value) keys values
  • sort using caclutated weights

enter image description here

Object.defineProperty(Array.prototype, 'orderBy', {
value: function(sorts) { 
    sorts.map(sort => {            
        sort.uniques = Array.from(
            new Set(this.map(obj => obj[sort.key]))
        );
        
        sort.uniques = sort.uniques.sort((a, b) => {
            if (typeof a == 'string') {
                return sort.inverse ? b.localeCompare(a) : a.localeCompare(b);
            }
            else if (typeof a == 'number') {
                return sort.inverse ? b - a : a - b;
            }
            else if (typeof a == 'boolean') {
                let x = sort.inverse ? (a === b) ? 0 : a? -1 : 1 : (a === b) ? 0 : a? 1 : -1;
                return x;
            }
            return 0;
        });
    });

    const weightOfObject = (obj) => {
        let weight = "";
        sorts.map(sort => {
            let zeropad = `${sort.uniques.length}`.length;
            weight += sort.uniques.indexOf(obj[sort.key]).toString().padStart(zeropad, '0');
        });
        //obj.weight = weight; // if you need to see weights
        return weight;
    }

    this.sort((a, b) => {
        return weightOfObject(a).localeCompare( weightOfObject(b) );
    });
    
    return this;
}
});

Use:

// works with string, number and boolean
let sortered = your_array.orderBy([
    {key: "type", inverse: false}, 
    {key: "title", inverse: false},
    {key: "spot", inverse: false},
    {key: "internal", inverse: true}
]);

enter image description here

Here's a generic multidimensional sort, allowing for reversing and/or mapping on each level.

Written in Typescript. For Javascript, check out this JSFiddle

The Code

type itemMap = (n: any) => any;

interface SortConfig<T> {
  key: keyof T;
  reverse?: boolean;
  map?: itemMap;
}

export function byObjectValues<T extends object>(keys: ((keyof T) | SortConfig<T>)[]): (a: T, b: T) => 0 | 1 | -1 {
  return function(a: T, b: T) {
    const firstKey: keyof T | SortConfig<T> = keys[0];
    const isSimple = typeof firstKey === 'string';
    const key: keyof T = isSimple ? (firstKey as keyof T) : (firstKey as SortConfig<T>).key;
    const reverse: boolean = isSimple ? false : !!(firstKey as SortConfig<T>).reverse;
    const map: itemMap | null = isSimple ? null : (firstKey as SortConfig<T>).map || null;

    const valA = map ? map(a[key]) : a[key];
    const valB = map ? map(b[key]) : b[key];
    if (valA === valB) {
      if (keys.length === 1) {
        return 0;
      }
      return byObjectValues<T>(keys.slice(1))(a, b);
    }
    if (reverse) {
      return valA > valB ? -1 : 1;
    }
    return valA > valB ? 1 : -1;
  };
}

Usage Examples

Sorting a people array by last name, then first name:

interface Person {
  firstName: string;
  lastName: string;
}

people.sort(byObjectValues<Person>(['lastName','firstName']));

Sort language codes by their name, not their language code (see map), then by descending version (see reverse).

interface Language {
  code: string;
  version: number;
}

// languageCodeToName(code) is defined elsewhere in code

languageCodes.sort(byObjectValues<Language>([
  {
    key: 'code',
    map(code:string) => languageCodeToName(code),
  },
  {
    key: 'version',
    reverse: true,
  }
]));

why complicate? just sort it twice! this works perfectly: (just make sure to reverse the importance order from least to most):

jj.sort( (a, b) => (a.id >= b.id) ? 1 : -1 );
jj.sort( (a, b) => (a.status >= b.status) ? 1 : -1 );

Just another option. Consider to use the following utility function:

/** Performs comparing of two items by specified properties
 * @param  {Array} props for sorting ['name'], ['value', 'city'], ['-date']
 * to set descending order on object property just add '-' at the begining of property
 */
export const compareBy = (...props) => (a, b) => {
  for (let i = 0; i < props.length; i++) {
    const ascValue = props[i].startsWith('-') ? -1 : 1;
    const prop = props[i].startsWith('-') ? props[i].substr(1) : props[i];
    if (a[prop] !== b[prop]) {
      return a[prop] > b[prop] ? ascValue : -ascValue;
    }
  }
  return 0;
};

Example of usage (in your case):

homes.sort(compareBy('city', '-price'));

It should be noted that this function can be even more generalized in order to be able to use nested properties like 'address.city' or 'style.size.width' etc.

simply follow the list of your sorting criteria

this code will always remain readable and understandable even if you have 36 sorting criteria to encase

The solution proposed here by Nina is certainly very elegant, but it implies knowing that a value of zero corresponds to a value of false in Boolean logic, and that Boolean tests can return something other than true / false in JavaScript (here are numeric values) which will always be confusing for a beginner.

Also think about who will need to maintain your code. Maybe it would be you: imagine yourself spending your days raking for days the code of another and having a pernicious bug ... and you are exhausted from reading these thousands of lines full of tips

const homes = 
  [ { h_id: '3', city: 'Dallas',       state: 'TX', zip: '75201', price: '162500' } 
  , { h_id: '4', city: 'Bevery Hills', state: 'CA', zip: '90210', price: '319250' } 
  , { h_id: '6', city: 'Dallas',       state: 'TX', zip: '75000', price: '556699' } 
  , { h_id: '5', city: 'New York',     state: 'NY', zip: '00010', price: '962500' } 
  ]
  
const fSort = (a,b) =>
  {
  let Dx = a.city.localeCompare(b.city)              // 1st criteria
  if (Dx===0) Dx = Number(b.price) - Number(a.price) // 2nd

  // if (Dx===0) Dx = ... // 3rd
  // if (Dx===0) Dx = ... // 4th....
  return Dx
  }

console.log( homes.sort(fSort))

// custom sorting by city
const sortArray = ['Dallas', 'New York', 'Beverly Hills'];

const sortData = (sortBy) =>
  data
    .sort((a, b) => {
      const aIndex = sortBy.indexOf(a.city);
      const bIndex = sortBy.indexOf(b.city);

      if (aIndex < bIndex) {
        return -1;
      }

      if (aIndex === bIndex) {
        // price descending
        return b.price- a.price;
      }

      return 1;
    });

sortData(sortArray);

Adding a couple helper functions lets you solved this kind of problem generically and simply. sortByKey takes an array and a function which should return a list of items with which to compare each array entry.

This takes advantage of the fact that javascript does smart comparison of arrays of simple values, with [2] < [2, 0] < [2, 1] < [10, 0].

// Two helpers:
function cmp(a, b) {
    if (a > b) {
        return 1
    } else if (a < b) {
        return -1
    } else {
        return 0
    }
}

function sortByKey(arr, key) {
    arr.sort((a, b) => cmp(key(a), key(b)))
}

// A demonstration:
let arr = [{a:1, b:2}, {b:3, a:0}, {a:1, b:1}, {a:2, b:2}, {a:2, b:1}, {a:1, b:10}]
sortByKey(arr, item => [item.a, item.b])

console.log(JSON.stringify(arr))
// '[{"b":3,"a":0},{"a":1,"b":1},{"a":1,"b":10},{"a":1,"b":2},{"a":2,"b":1},{"a":2,"b":2}]'

sortByKey(arr, item => [item.b, item.a])
console.log(JSON.stringify(arr))
// '[{"a":1,"b":1},{"a":2,"b":1},{"a":1,"b":10},{"a":1,"b":2},{"a":2,"b":2},{"b":3,"a":0}]'

I've lovingly stolen this idea from Python's list.sort function.

Wow, there are some complex solutions here. So complex I decided to come up with something simpler but also quite powerful. Here it is;

function sortByPriority(data, priorities) {
  if (priorities.length == 0) {
    return data;
  }

  const nextPriority = priorities[0];
  const remainingPriorities = priorities.slice(1);

  const matched = data.filter(item => item.hasOwnProperty(nextPriority));
  const remainingData = data.filter(item => !item.hasOwnProperty(nextPriority));

  return sortByPriority(matched, remainingPriorities)
    .sort((a, b) => (a[nextPriority] > b[nextPriority]) ? 1 : -1)
    .concat(sortByPriority(remainingData, remainingPriorities));
}

And here is an example of how you use it.

const data = [
  { id: 1,                         mediumPriority: 'bbb', lowestPriority: 'ggg' },
  { id: 2, highestPriority: 'bbb', mediumPriority: 'ccc', lowestPriority: 'ggg' },
  { id: 3,                         mediumPriority: 'aaa', lowestPriority: 'ggg' },
];

const priorities = [
  'highestPriority',
  'mediumPriority',
  'lowestPriority'
];


const sorted = sortByPriority(data, priorities);

This will first sort by the precedence of the attributes, then by the value of the attributes.

I think this may be the easiest way to do it.

https://coderwall.com/p/ebqhca/javascript-sort-by-two-fields

It's really simple and I tried it with 3 different key value pairs and it worked great.

Here is a simple example, look at the link for more details

testSort(data) {
    return data.sort(
        a['nameOne'] > b['nameOne'] ? 1
        : b['nameOne'] > a['nameOne'] ? -1 : 0 ||
        a['date'] > b['date'] ||
        a['number'] - b['number']
    );
}

Here is mine for your reference, with example:

function msort(arr, ...compFns) {
  let fn = compFns[0];
  arr = [].concat(arr);
  let arr1 = [];
  while (arr.length > 0) {
    let arr2 = arr.splice(0, 1);
    for (let i = arr.length; i > 0;) {
      if (fn(arr2[0], arr[--i]) === 0) {
        arr2 = arr2.concat(arr.splice(i, 1));
      }
    }
    arr1.push(arr2);
  }

  arr1.sort(function (a, b) {
    return fn(a[0], b[0]);
  });

  compFns = compFns.slice(1);
  let res = [];
  arr1.map(a1 => {
    if (compFns.length > 0) a1 = msort(a1, ...compFns);
    a1.map(a2 => res.push(a2));
  });
  return res;
}

let tstArr = [{ id: 1, sex: 'o' }, { id: 2, sex: 'm' }, { id: 3, sex: 'm' }, { id: 4, sex: 'f' }, { id: 5, sex: 'm' }, { id: 6, sex: 'o' }, { id: 7, sex: 'f' }];

function tstFn1(a, b) {
  if (a.sex > b.sex) return 1;
  else if (a.sex < b.sex) return -1;
  return 0;
}

function tstFn2(a, b) {
  if (a.id > b.id) return -1;
  else if (a.id < b.id) return 1;
  return 0;
}

console.log(JSON.stringify(msort(tstArr, tstFn1, tstFn2)));
//output:
//[{"id":7,"sex":"f"},{"id":4,"sex":"f"},{"id":5,"sex":"m"},{"id":3,"sex":"m"},{"id":2,"sex":"m"},{"id":6,"sex":"o"},{"id":1,"sex":"o"}]

I was looking for something similar and ended up with this:

First we have one or more sorting functions, always returning either 0, 1 or -1:

const sortByTitle = (a, b): number => 
  a.title === b.title ? 0 : a.title > b.title ? 1 : -1;

You can create more functions for each other property you want to sort on.

Then I have a function that combines these sorting functions into one:

const createSorter = (...sorters) => (a, b) =>
  sorters.reduce(
    (d, fn) => (d === 0 ? fn(a, b) : d),
    0
  );

This can be used to combine the above sorting functions in a readable way:

const sorter = createSorter(sortByTitle, sortByYear)

items.sort(sorter)

When a sorting function returns 0 the next sorting function will be called for further sorting.

This is a recursive algorithm to sort by multiple fields while having the chance to format values before comparison.

var data = [
{
    "id": 1,
    "ship": null,
    "product": "Orange",
    "quantity": 7,
    "price": 92.08,
    "discount": 0
},
{
    "id": 2,
    "ship": "2017-06-14T23:00:00.000Z".toDate(),
    "product": "Apple",
    "quantity": 22,
    "price": 184.16,
    "discount": 0
},
...
]
var sorts = ["product", "quantity", "ship"]

// comp_val formats values and protects against comparing nulls/undefines
// type() just returns the variable constructor
// String.lower just converts the string to lowercase.
// String.toDate custom fn to convert strings to Date
function comp_val(value){
    if (value==null || value==undefined) return null
    var cls = type(value)
    switch (cls){
        case String:
            return value.lower()
    }
    return value
}

function compare(a, b, i){
    i = i || 0
    var prop = sorts[i]
    var va = comp_val(a[prop])
    var vb = comp_val(b[prop])

    // handle what to do when both or any values are null
    if (va == null || vb == null) return true

    if ((i < sorts.length-1) && (va == vb)) {
        return compare(a, b, i+1)
    } 
    return va > vb
}

var d = data.sort(compare);
console.log(d);

If a and b are equal it will just try the next field until none is available.

You can use lodash orderBy function lodash

It takes two params array of fields, and array of directions ('asc','desc')

  var homes = [
    {"h_id":"3",
     "city":"Dallas",
     "state":"TX",
     "zip":"75201",
     "price":"162500"},
    {"h_id":"4",
     "city":"Bevery Hills",
     "state":"CA",
     "zip":"90210",
     "price":"319250"},
    {"h_id":"6",
     "city":"Dallas",
     "state":"TX",
     "zip":"75000",
     "price":"556699"},
    {"h_id":"5",
     "city":"New York",
     "state":"NY",
     "zip":"00010",
     "price":"962500"}
    ];

var sorted =. data._.orderBy(data, ['city', 'price'], ['asc','desc'])

A very intuitive functional solution can be crafted by adding 3 relatively simple helpers. Before we dive in, let's start with the usage:

function usage(homes, { asc, desc, fallback }) {
  homes.sort(fallback(
    asc(home => home.city),
    desc(home => parseInt(home.price, 10)),
  ));
  console.log(homes);
}

var homes = [{
  h_id:  "3",
  city:  "Dallas",
  state: "TX",
  zip:   "75201",
  price: "162500",
}, {
  h_id:  "4",
  city:  "Bevery Hills",
  state: "CA",
  zip:   "90210",
  price: "319250",
}, {
  h_id:  "6",
  city:  "Dallas",
  state: "TX",
  zip:   "75000",
  price: "556699",
}, {
  h_id:  "5",
  city:  "New York",
  state: "NY",
  zip:   "00010",
  price: "962500",
}];

const SortHelpers = (function () {
  const asc  = (fn) => (a, b) => (a = fn(a), b = fn(b), -(a < b) || +(a > b));
  const desc = (fn) => (a, b) => asc(fn)(b, a);
  const fallback = (...fns) => (a, b) => fns.reduce((diff, fn) => diff || fn(a, b), 0);
  return { asc, desc, fallback };
})();

usage(homes, SortHelpers);

If you scrolled down the snippet you probably already saw the helpers:

const asc  = (fn) => (a, b) => (a = fn(a), b = fn(b), -(a < b) || +(a > b));
const desc = (fn) => (a, b) => asc(fn)(b, a);
const fallback = (...fns) => (a, b) => fns.reduce((diff, fn) => diff || fn(a, b), 0);

Let me quickly explain what each of these functions does.

  • asc creates a comparator function. The provided function fn is called with both the comparator arguments a and b. The results of the two function calls are then compared. -1 is returned if resultA < resultB, 1 is returned if resultA > resultB, or 0 if both are false. These return values correspond with an ascending order direction.

    It could also be written like this:

    function asc(fn) {
      return function (a, b) {
        // apply `fn` to both `a` and `b`
        a = fn(a);
        b = fn(b);
    
        if (a < b) return -1;
        if (a > b) return  1;
        return 0;
        // or `return -(a < b) || +(a > b)` for short
      };
    }
    
  • desc is super simple, since it just calls asc but swaps the a and b arguments, resulting in descending order instead of ascending.

  • fallback (there might be a better name for this) allows us to use multiple comparator functions with a single sort.

    Both asc and desc can be passed to sort by themself.

    homes.sort(asc(home => home.city))
    

    There is however an issue if you want to combine multiple comparator functions. sort only accepts a single comparator function. fallback combines multiple comparator functions into a single comparator.

    The first comparator is called with arguments a and b, if the comparator returns the value 0 (meaning that the values are equal) then we fall back to the next comparator. This continues until a non-0 value is found, or until all comparators are called, in which case the return value is 0.

You provide your custom comparator functions super simple. Say you want to use localeCompare() instead of comparing strings with < and >. In such a case you can simply replace asc(home => home.city) with (a, b) => a.city.localeCompare(b.city).

homes.sort(fallback(
  (a, b) => a.city.localeCompare(b.city),
  desc(home => parseInt(home.price, 10)),
));

One thing to note is that values that can be undefined will always return false when comparing with < and >. So if a value can be missing you might want to sort by its presence first.

homes.sort(fallback(
  // homes with optionalProperty first, true (1) > false (0) so we use desc
  desc(home => home.optionalProperty != null), // checks for both null and undefined
  asc(home => home.optionalProperty),
  // ...
))

Here, you can try the smaller and convenient way to sort by multiple fields!

var homes = [
    {"h_id":"3",
     "city":"Dallas",
     "state":"TX",
     "zip":"75201",
     "price":"162500"},
    {"h_id":"4",
     "city":"Bevery Hills",
     "state":"CA",
     "zip":"90210",
     "price":"319250"},
    {"h_id":"6",
     "city":"Dallas",
     "state":"TX",
     "zip":"75000",
     "price":"556699"},
    {"h_id":"5",
     "city":"New York",
     "state":"NY",
     "zip":"00010",
     "price":"962500"}
    ];

homes.sort((a, b)=> {
  if (a.city === b.city){
    return a.price < b.price ? -1 : 1
  } else {
    return a.city < b.city ? -1 : 1
  }
})

console.log(homes);

How about this simple solution:

const sortCompareByCityPrice = (a, b) => {
    let comparison = 0
    // sort by first criteria
    if (a.city > b.city) {
        comparison = 1
    }
    else if (a.city < b.city) {
        comparison = -1
    }
    // If still 0 then sort by second criteria descending
    if (comparison === 0) {
        if (parseInt(a.price) > parseInt(b.price)) {
            comparison = -1
        }
        else if (parseInt(a.price) < parseInt(b.price)) {
            comparison = 1
        }
    }
    return comparison 
}

Based on this question javascript sort array by multiple (number) fields

Simplest Way to sort array of object by multiple fields:

 let homes = [ {"h_id":"3",
   "city":"Dallas",
   "state":"TX",
   "zip":"75201",
   "price":"162500"},
  {"h_id":"4",
   "city":"Bevery Hills",
   "state":"CA",
   "zip":"90210",
   "price":"319250"},
  {"h_id":"6",
   "city":"Dallas",
   "state":"TX",
   "zip":"75000",
   "price":"556699"},
  {"h_id":"5",
   "city":"New York",
   "state":"NY",
   "zip":"00010",
   "price":"962500"}
  ];

homes.sort((a, b) => (a.city > b.city) ? 1 : -1);

Output: "Bevery Hills" "Dallas" "Dallas" "Dallas" "New York"

Related