How to sort and get max value from 3 array of objects in javascript and assign it to another array?

Question

How to sort and get max value from 3 array of objects and assign the keys and values to another array?

I want to sort the arrays test1, test2, test3 and get the max score for a student and assign it to the array results as an object like

results = [{name: name, score: score}]

I am able to get the highest score out of all the tests but finding it a bit difficult to get the names and assigning it as an object to the results array

const test1 = [{name: 'vikash', score: 1}, {name: 'krish', score: 2}, {name: 'kunz', score: 3}]
const test2 = [{name: 'kunz', score: 4}, {name: 'vikash', score: 5}, {name: 'krish', score: 6}]
const test3 = [{name: 'krish', score: 7}, {name: 'kunz', score: 8}, {name: 'vikash', score: 9}]

const results = []

const maxScore = Math.max(Math.max(...test1.map(test => test.score)), Math.max(...test2.map(test => test.score)), Math.max(...test3.map(test => test.score)));

// prints highest score out of the 3 tests: 9
console.log(maxScore )

The results array should look like this at the end of it ..

resutls = [{name: 'vikash', score: 9}]

zer00ne · Accepted Answer · 2020-04-22 03:39:03Z

Use the spread operator at parameter so that you can accept multiple arrays
```
const topScore = (...arrays) => { ...
```
Then wrap the arrays in a bracket and prefix with the spread operator and for good measure flatten the result
```
[...arrays].flat()....

// returns arrayOfObjects = [{object}, {object}, ....{object}]
```
Finally, compare each objects score value (obj.value) in .reduce()
```
arrayOfObjects.reduce((max, obj) => {
  return max.score < obj.score ? obj : max;
...
```
The ternary compares the current obj.score vs. the obj with the greatest score from past iterations. The obj with the higher score stays or becomes max.
BTW, I just noticed that the desired answer is the object within array. I have edited the demo to do so.

Demo

const test1 = [{name: 'vikash', score: 1}, {name: 'krish', score: 2}, {name: 'kunz', score: 3}];
const test2 = [{name: 'kunz', score: 10}, {name: 'vikash', score: 5}, {name: 'krish', score: 6}];
const test3 = [{name: 'krish', score: 7}, {name: 'kunz', score: 8}, {name: 'vikash', score: 9}];

const topScore = (...arrays) => {
  let result = [...arrays].flat().reduce((max, obj) => {
    return max.score < obj.score ? obj : max;
  });
  return [result];
};

console.log(topScore(test1, test2, test3));

Luís Ramalho · Accepted Answer · 2020-04-22 03:06:56Z

1

You could do something like the following:

const test1 = [
  { name: "vikash", score: 1 },
  { name: "krish", score: 2 },
  { name: "kunz", score: 3 },
];
const test2 = [
  { name: "kunz", score: 4 },
  { name: "vikash", score: 5 },
  { name: "krish", score: 6 },
];
const test3 = [
  { name: "krish", score: 7 },
  { name: "kunz", score: 8 },
  { name: "vikash", score: 9 },
];

let results = [
  [...test1, ...test2, ...test3].reduce((p, c) => {
    return p.score > c.score ? p : c;
  }),
];

console.log(results);

Basically, you reduce the spreaded arrays and then for each object you check its score, if more than the previous then that's the highest and should be returned.

I've wrapped everything in an array so that the output is an array.

edited Apr 22, 2020 at 3:06

answered Apr 22, 2020 at 2:49

Luís Ramalho

10.2k4 gold badges54 silver badges69 bronze badges

1 Comment

Luís Ramalho Over a year ago

Yes, you definitely can use this for as many test arrays as you want, you just need to spread them.

Collectives™ on Stack Overflow

How to sort and get max value from 3 array of objects in javascript and assign it to another array?

2 Answers 2

Demo

Comments

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Demo

Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related