Javascript: How to compare two arrays, and return the name of the array with highest value in a certain index

Question

I have been working on the scoring system for a game I am building with Javascript and have run into a problem. I am trying to compare the index 0 of a couple of arrays and return the index 1 of the array with the highest value.

This is what I have so far:

var player1 = new Array [1, "billy"];
var player2 = new Array [2, "jean"];

function checkWinner() {
    var winner = Math.max(player1[0], player2[0]);
    console.log(winner[1]);
}

checkWinner();

You can't use `new Array []` to instantiate arrays. Use `new Array()` or `[]`. [Here's the difference](https://stackoverflow.com/q/931872/8289918). — cherryblossom, May 05 '20 at 00:00

jshawl · Answer 1 · 2020-05-07T02:33:42.213

1

I really like reduce as an option here. It goes through each of the players 1 by 1 and if the current player has a higher score than the previous player, then the current player has the highest score (and at the end will be the winner).

const players = [
  {
    name: "billy",
    score: 3
  },
  {
    name: "jean",
    score: 2
  }
];

const getWinner = players => players.reduce((currentWinner, player) => 
  player.score > currentWinner.score ? player : currentWinner
)
const winner = getWinner(players)
console.log(`The winner is: ${winner.name}!`)

I also changed the array of (score, name) to be an object with keys "score" and "name" to be able to reference those values later with out brackets.

edited May 07 '20 at 02:33

answered May 05 '20 at 00:37

jshawl

2,828
2
19
31

I think you meant `currentWinner` instead of `acc` in `player.score > currentWinner.score ? player : acc`. – cherryblossom May 07 '20 at 01:57
thank you for pointing this out! I have edited the above answer – jshawl May 07 '20 at 02:34

score 0 · Answer 2 · answered May 04 '20 at 23:47

In your code the variable winner will be an integer that is the larger of the 2 scores. It's not an array that you can get index 1 from. You want to get the player Array that has the higher score, not the score itself. You can do that like this:

function checkWinner() {
    var winner = player1;
    if (player1[0] < player2[0]) {
        winner = player2;
    }
    console.log(winner[1]);
}

This doesn't handle the case where there is a tie, but you can add an if-statement for that also.

score 0 · Answer 3 · answered May 04 '20 at 23:50

0

You can do a simple if:

function checkWinner() {
var winner;
if (player1[0] < player2[0]) {
    winner = player2;
}else{
    winner = player1;
}

console.log(winner[1]);

}

answered May 04 '20 at 23:50

Jacopo Mosconi

228
2
12

score 0 · Accepted Answer · answered May 04 '20 at 23:59

Bonus: check the winner of any number of players:

var player1 = [1, "billy"];
var player2 = [2, "jean"];

function checkWinner() {
    var players = Array.prototype.slice.call(arguments);
    var max = Math.max.apply(null, players.map(function (p) {
        return p[0];
    }));
    var winner = players.filter(function (p) {
        return p[0] === max;
    })[0];
    console.log(winner[1]);
}

checkWinner(player1, player2);

ES2015:

const player1 = [1, "billy"];
const player2 = [2, "jean"];

const checkWinner = (...players) => {
    const max = Math.max(...players.map(p => p[0]));
    const winner = players.find(p => p[0] === max);
    console.log(winner[1]);
}

checkWinner(player1, player2);

Javascript: How to compare two arrays, and return the name of the array with highest value in a certain index

4 Answers4