Sort array of objects based on another array

Question

I have a array of makes as follows:

const makes = [
{id: "4", name: "Audi"},
{id: "5", name: "Bmw"},
{id: "6", name: "Porsche"},
{id: "31", name: "Seat"},
{id: "32", name: "Skoda"},
{id: "36", name: "Toyota"},
{id: "38", name: "Volkswagen"}
]

And I want to sort that array based on another array:

const preferred_makes = ['Volkswagen', 'Audi'];

What I do now is as follows:

const preferred_makes = ['Volkswagen', 'Audi'];

const makes = [
{id: "4", name: "Audi"},
{id: "5", name: "Bmw"},
{id: "6", name: "Porsche"},
{id: "31", name: "Seat"},
{id: "32", name: "Skoda"},
{id: "36", name: "Toyota"},
{id: "38", name: "Volkswagen"}
]

const mainMakes = []
const otherMakes = []

makes.map(make => _.includes(preferred_makes, make.name) ? mainMakes.push(make) : otherMakes.push(make))

console.log(mainMakes)
console.log(otherMakes)

But is there any better way? Can I sort makes to show those preferred_makes as first elements of the array?

Here is the fiddle.

Answer 1

You could take an object with the by one incremented indices and take a default value of Infinity for not found names. Then sort by the delta of the values.

 var preferred_makes = ['Volkswagen', 'Audi'], preferred = preferred_makes.reduce((o, k, i) => (o[k] = i + 1, o), {}); array = [{ id: "4", name: "Audi" }, { id: "5", name: "Bmw" }, { id: "6", name: "Porsche" }, { id: "31", name: "Seat" }, { id: "32", name: "Skoda" }, { id: "36", name: "Toyota" }, { id: "38", name: "Volkswagen" }]; array.sort((a, b) => (preferred[a.name] || Infinity) - (preferred[b.name] || Infinity)); console.log(array); 

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

Answer 2

A regular array.sort() with a custom comparison function should be able to do this.

 const preferred_makes = ['Volkswagen', 'Audi']; const makes = [ {id: "4", name: "Audi"}, {id: "5", name: "Bmw"}, {id: "6", name: "Porsche"}, {id: "31", name: "Seat"}, {id: "32", name: "Skoda"}, {id: "36", name: "Toyota"}, {id: "38", name: "Volkswagen"} ] const sorted = makes.slice().sort((a, b) => { // Convert true and false to 1 and 0 const aPreferred = new Number(preferred_makes.includes(a.name)) const bPreferred = new Number(preferred_makes.includes(b.name)) // Return 1, 0, or -1 return bPreferred - aPreferred }) console.log(sorted) 

Answer 3

You could use reduce to make two arrays without the requirement for sorting:

 const preferred_makes = ['Volkswagen','Audi']; const makes = [{id:"4",name:"Audi"},{id:"5",name:"Bmw"},{id:"6",name:"Porsche"},{id:"31",name:"Seat"},{id:"32",name:"Skoda"},{id:"36",name:"Toyota"},{id:"38",name:"Volkswagen"}]; const [mainMakes, otherMakes] = makes.reduce(([a, b], { id, name }) => ((preferred_makes.includes(name) ? a : b).push({ id, name }), [a, b]), [[], []]); console.log(mainMakes); console.log(otherMakes); 

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

To make it even faster, you could Set.prototype.has instead of includes :

 const preferred_makes = new Set(['Volkswagen','Audi']); const makes = [{id:"4",name:"Audi"},{id:"5",name:"Bmw"},{id:"6",name:"Porsche"},{id:"31",name:"Seat"},{id:"32",name:"Skoda"},{id:"36",name:"Toyota"},{id:"38",name:"Volkswagen"}]; const [mainMakes, otherMakes] = makes.reduce(([a, b], { id, name }) => ((preferred_makes.has(name) ? a : b).push({ id, name }), [a, b]), [[], []]); console.log(mainMakes); console.log(otherMakes); 

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

Answer 4

You can also sort by the Array.indexOf if the index is there otherwise use String.localeCompare . No real need for lodash really:

 const makes = [ {id: "4", name: "Audi"}, {id: "6", name: "Porsche"}, {id: "31", name: "Seat"}, {id: "32", name: "Skoda"}, {id: "5", name: "Bmw"}, {id: "36", name: "Toyota"}, {id: "38", name: "Volkswagen"} ] const list = ['Volkswagen', 'Audi']; let result = makes.sort((a,b) => { let i = list.indexOf(a.name) return i < 0 ? a.name.localeCompare(b.name) : list.indexOf(b.name) - i }) console.log(result) 

Answer 5

With lodash you can generate a dictionary of the original index by the car's make ( indexByMake ) using _.invert() to get an object of { [car make]: original array index } , and map the values back to numbers.

Use _.orderBy() to sort the array, and use the values from indexByMake according to the name :

 const preferred_makes = ['Volkswagen', 'Audi']; const array = [{ id: "4", name: "Audi" }, { id: "5", name: "Bmw" }, { id: "6", name: "Porsche" }, { id: "31", name: "Seat" }, { id: "32", name: "Skoda" }, { id: "36", name: "Toyota" }, { id: "38", name: "Volkswagen" }]; const indexByMake = _.mapValues(_.invert(preferred_makes), Number); const result = _.sortBy(array, ({ name }) => indexByMake[name]); console.log(result); 

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

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