Getting max value(s) in JSON array

Question

I\'m trying to create a JavaScript function which takes information from an array in an external JSON and then takes the max value (or the top 5 values) for one of the JSON

Answer 1

This will allow you to choose what stat you want and what information you want back.

http://jsbin.com/tudegofa/1/edit

data => is the array

stat => is the stat you want to sort by

info => is an array of properties you want returned.

function getValues (data, stat, info)
{
  var selectedValues = data.map(function(x) {
    return parseFloat(x[stat]);
  })

  var i = selectedValues.indexOf(Math.max.apply(Math, selectedValues));

  var result = {};
  info.forEach(function(x) {
      result[x] = test[i][x];
  })
  return result;
}

var myData = '';
$.getJSON('/url/to/grab/json', function(data) {

  myData = data;

});

getValues(myData, "bpg", ["player","team"]);

//[object Object] {
//  player: "Anthony Davis",
//  team: "New Orleans Pelicans"
// }

Answer 2

My solution here. Remember to use == instead of === to compare a number with a string.

const getMax = (arr, prop) => {
  const tmp = arr.map(x => x[prop]);
  const max = Math.max(...tmp);
  return arr.filter(x => x[prop] == max);
}

getMax(myArr,"bpg")

One line version:

myArr.filter( x => x["bpg"] == Math.max(...myArr.map(x => x["bpg"])) )

Answer 3

I found the following approach very neat:

arr.sort( 
  function(a, b) {
     return parseFloat(b['ppg']) - parseFloat(a['ppg']);
  }
)[0]['player']

Demo in snippet:

var arr =[
{
    "player" : "Andre Drummond",
    "team" : "Detroit Pistons",
    "ppg" : "15.4",
    "rpg" : "11.6",
    "apg" : "2.4",
    "bpg" : "1.6",
    "spg" : "0.8",
    "3pg" : "0.1"
},
{
    "player" : "Anthony Davis",
    "team" : "New Orleans Pelicans",
    "ppg" : "16.4",
    "rpg" : "13.6",
    "apg" : "2.6",
    "bpg" : "3.5",
    "spg" : "1.2",
    "3pg" : "0.1"
},
{
    "player" : "Carmelo Anthony",
    "team" : "New York Knicks",
    "ppg" : "27.4",
    "rpg" : "5.4",
    "apg" : "4.5",
    "bpg" : "1.1",
    "spg" : "1.5",
    "3pg" : "1.6"
}
]
console.log(
arr.sort( 
    function(a, b) {
       return parseFloat(b['ppg']) - parseFloat(a['ppg']);
    }
    )[0]['player']
);

First, I sort the array in descending order, then I choose the first element which contains the max value. In the code, I found the player who has the max ppg value. Hope this helps!

Answer 4

Simplicity thanks you in the long run.

function getMaxValueByAttribute(arr, attr) {
    var max = "-99999999999";
    arr.forEach(function (member, index) {
            // console.log(member, index);
            if (member.hasOwnProperty(attr) && parseFloat(member[attr]) > parseFloat(max)) {
                max = member[attr];
                // console.log("Max now: " + max);
            }
        });
    return max;
    }

Then use it like:

var result = getMaxValueByAttribute(arr, "ppg");
// result = "27.4"

Answer 5

the more simple:

const players =                                           
  [ { player: 'Andre Drummond',  team: 'Detroit Pistons',      ppg: '15.4', rpg: '11.6', apg: '2.4', bpg: '1.6', spg: '0.8', '3pg': '0.1' } 
  , { player: 'Anthony Davis',   team: 'New Orleans Pelicans', ppg: '16.4', rpg: '13.6', apg: '2.6', bpg: '3.5', spg: '1.2', '3pg': '0.1' } 
  , { player: 'Carmelo Anthony', team: 'New York Knicks',      ppg: '27.4', rpg: '5.4',  apg: '4.5', bpg: '1.1', spg: '1.5', '3pg': '1.6' } 
  ] 

const getPlayerMax_on = cod => players.reduce((a,c)=>((+a[cod])<(+c[cod]))?c:a)

const maxOn_ppg = getPlayerMax_on('ppg')

console.log( maxOn_ppg.player, maxOn_ppg.team, maxOn_ppg.ppg )