Sort an array of strings based on an array of numbers

Question

I am trying to do the following operation: sort an array of strings based on an array of numbers of equal length. For example:

A=[a,b,c,d,e]
B=[1,3,2,5,4]

A'=[a,c,b,e,d] //<=The desired outcome

Basically, I am thinking about sorting the array A based on sorting array B into ascending order. Here, I am thinking about implicit value pairs, just like objects.

I can think of creating an object, sorting it, and then separating out the array of strings, but this is probably too much code and am wondering if there is a simpler method to achieve this.
Any advice will be welcome. Thank you very much!

"...creating an object, sorting it,..." - You cannot "sort" an object. — Andreas
– Andreas, Commented Feb 21, 2020 at 11:32
Try this A.map((x,y)=>{return {"string":x,"number":B[y]}}).sort((x,y)=>x.number-y.number).map(x=>x.string) — Sourabh Somani
– Sourabh Somani, Commented Feb 21, 2020 at 11:36

Andreas · Accepted Answer · 2020-02-21 14:34:33Z

5

You don't need to sort anything here.
Just use the numbers as "positions" from where to get the value for the current index/position in the result.

const input = ["a", "b", "c", "d", "e"];
const order = [1, 3, 2, 5, 4];

const result = order.map(position => input[position - 1]);

console.log(result);

edited Feb 21, 2020 at 14:34

answered Feb 21, 2020 at 11:39

Andreas

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1 Comment

Sourabh Somani Over a year ago

Awesome reply really I was not thinking about this

TKoL · Accepted Answer · 2020-02-21 11:40:06Z

1

A little bit of code golf:

const A=['a','b','c','d','e'];
const B=[1,3,2,5,4];

// for this to work, we have to assume A and B have the same length
// if you implement this into a function, do such a check yourself first

const sorted = A.map((item, index, arr) => arr[B[index] - 1]);
console.log(sorted);

This will work as long as B is AT LEAST as long as A, and if B is filled with numbers

answered Feb 21, 2020 at 11:40

TKoL

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Comments

StepUp · Accepted Answer · 2020-02-21 11:54:24Z

0

If you want to have a custom order, then you can create an object with order:

let a = ['a', 'b', 'c', 'd', 'e'];
let b = [1, 3, 2, 5, 4];

let order = {a: 1, b: 3, c:2, d: 5, e:4};

const result =  a.sort((a, b) => order[a] - order[b]);
console.log(result);

answered Feb 21, 2020 at 11:54

StepUp

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The fourth bird · Accepted Answer · 2020-02-21 13:21:02Z

0

You might use a for loop and add the value from A getting the index from B.

let A = ["a", "b", "c", "d", "e"];
let B = [1, 3, 2, 5, 4];
let C = [];

for (let i = 0; i < A.length; i++) C[B[i] - 1] = A[i];

console.log(C);

edited Feb 21, 2020 at 13:21

answered Feb 21, 2020 at 11:45

The fourth bird

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