CODEWITHSUNDEEP
javascriptarraysecmascript-6array.prototype.map
wycherley22
wycherley22

Reputation: 69

Return object with highest value from multiple arrays of objects

I have an array with multiple arrays of objects and Im trying to find the object with the highest value.

values = [
[ {_: "NAN", id: 1},
  {_: "NAN", id: 2},
  {_: "NAN", id: 3}
],
[{_: "3.006", id: 4},
 {_: "7.206", id: 5},
 {_: "1.906", id: 6}
],
[{_: "3.226", id: 7},
 {_: "2.222", id: 8}
 {_: "2.224", id: 9}
],
[{_: "0.006", id: 10},
 {_: "0.321", id: 11},
 {_: "0.938", id: 12}
]]

i tried to use .map and .find

        var a = Math.max(...values.map(e => e._))
        const highestPoint = values.find(values => values._ === a)

But its only bringing back NAN as highest point const highestPoint = {_: "NAN", id: 1}, like its only looking through the first array?

Upvotes: 2

Views: 767

Answers (4)

xdeepakv
xdeepakv

Reputation: 8135

Simple and fast enough:

const max = (arr = []) => {
  return arr.reduce(
    (m, i) => {
      i.forEach((x) => {
        if (x._ !== 'NAN' && m._ < x._) {
          m = x;
        }
      });
      return m;
    },
    { _: -Infinity }
  );
};


const max = (arr = []) => {
  return arr.reduce(
    (m, i) => {
      i.forEach((x) => {
        if (x._ !== 'NAN' && m._ < x._) {
          m = x;
        }
      });
      return m;
    },
    { _: -Infinity }
  );
};
const data = [
  [
    { _: "NAN", id: 1 },
    { _: "NAN", id: 2 },
    { _: "NAN", id: 3 },
  ],
  [
    { _: "3.006", id: 4 },
    { _: "7.206", id: 5 },
    { _: "1.906", id: 6 },
  ],
  [
    { _: "3.226", id: 7 },
    { _: "2.222", id: 8 },
    { _: "2.224", id: 9 },
  ],
  [
    { _: "0.006", id: 10 },
    { _: "0.321", id: 11 },
    { _: "0.938", id: 12 },
  ],
];
console.log(max(data));

Upvotes: 0

Nina Scholz
Nina Scholz

Reputation: 386868

You could flat the arrays and take a filter with isFinite and reduce the array.

var values = [[{ _: "NAN", id: 1 }, { _: "NAN", id: 2 }, { _: "NAN", id: 3 }], [{ _: "3.006", id: 4 }, { _: "7.206", id: 5 }, { _: "1.906", id: 6 } ], [{ _: "3.226", id: 7 }, { _: "2.222", id: 8 }, { _: "2.224", id: 9 }], [{ _: "0.006", id: 10 }, { _: "0.321", id: 11 }, { _: "0.938", id: 12 }]],
    highest = values
        .flat()
        .filter(({ _ }) => isFinite(_))
        .reduce((a, b) => +a._ > +b._ ? a : b);

console.log(highest);

Upvotes: 3

Radu Diță
Radu Diță

Reputation: 14211

When any of the arguments to Math.max is not a number the result will be NaN.

You have an array of arrays, so when mapping you get arrays as the argument to Math.max so you need to filter the data and then pass it to max.

Something like this should work

values.flat().filter(item => !isNaN(Number(item._)))

Then you can pass this to max and will work.

Upvotes: 0

symlink
symlink

Reputation: 12208

You can do this with Array.flatMap() and Array.map() to put all the objects into one array, Array.filter() to remove the objects with "NAN", then Array.reduce to find the highest number:

let vals=[[{_:"NAN",id:1},{_:"NAN",id:2},{_:"NAN",id:3}],[{_:"3.006",id:4},{_:"7.206",id:5},{_:"1.906",id:6}],[{_:"3.226",id:7},{_:"2.222",id:8},{_:"2.224",id:9}],[{_:"0.006",id:10},{_:"0.321",id:11},{_:"0.938",id:12}]];

let res = vals.flatMap(arr => {
    return arr.map(obj => obj)
}).filter(obj => obj._ != "NAN").reduce((prv,cur) => prv._ > cur._ ? prv : cur)

console.log(res)

Upvotes: 0

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