Home / Questions / 497898
Accepted
Naidamag
Asked: 2022-04-18 14:32:47 +0800 CST 2022-04-18 14:32:47 +0800 CST

How to add properties of an object?

  • 772

I have 3 results with the properties teams and medals: Gold, bronze and silver. I need to total the medals by country, that is, add the 3 types of medals and assign the value to each corresponding country.

I can't use neither libraries nor regular expressions.

If you can help me, I appreciate it.

Estos son mis objetos: 

0: [{team: 'JOR', medal: 'Gold', total: 1}
1: {team: 'GBR', medal: 'Gold', total: 64}
2: {team: 'USA', medal: 'Gold', total: 139}]

0: [{team: 'JOR', medal: 'Silver', total: 55}
1: {team: 'GBR', medal: 'Silver', total: 28}
2: {team: 'USA', medal: 'Silver', total: 25}]

0: {team: 'JOR', medal: 'Bronze', total: 24}
1: {team: 'GBR', medal: 'Bronze', total: 10}
2: {team: 'USA', medal: 'Bronze', total: 4}

Necesito este resultado 

0: {team: 'JOR', totalMedals: 80}
1: {team: 'GBR', totalMedals: 102}
2: {team: 'USA', totalMedals: 168}

This is my code:

const computeData = (datos, medal) => { 
  const arrayOfNoc = [];
  const countriesWonMedals = datos.filter(athletes => athletes.medal === medal) 
  for (let i = 0; i < countriesWonMedals.length; i++) { 
    arrayOfNoc.push(countriesWonMedals[i].noc) 
  }
  const teamWithMedals = []; 
  for (let j = 0; j < arrayOfNoc.length; j++) { 
    const totalTeamWithMedals = arrayOfNoc[j] + " "+ medal + " " + arrayOfNoc.filter(team => team === arrayOfNoc[j]).length 
    teamWithMedals.push(totalTeamWithMedals) 
  }
 const eliminatingDuplicateTeams = new Set(teamWithMedals); 
 let newArrayTeamWithMedals = Array.from(eliminatingDuplicateTeams); 
 
   let creatingNewObject = newArrayTeamWithMedals.map(country => ( {      
    team: country.split(" ")[0],    
    medal: country.split(" ")[1],    
    total: Number(country.split(" ")[2])  
  }))
javascript

2 Answers

  1. Best Answer

    You can help yourself with an auxiliary structure to save the total results.

    On the other hand, since you want to know the total, you can unify all the results of each type of medal in a single array.

    Once that is done, you could use a reduce, but to simplify it, I leave you this option:

    // datos
const goldMedals = [
  {team: 'JOR', medal: 'Gold', total: 1},
  {team: 'GBR', medal: 'Gold', total: 64},
  {team: 'USA', medal: 'Gold', total: 139}
];

const silverMedals = [
  {team: 'JOR', medal: 'Silver', total: 55},
  {team: 'GBR', medal: 'Silver', total: 28},
  {team: 'USA', medal: 'Silver', total: 25}
];  

const bronzeMedals = [
  {team: 'JOR', medal: 'Bronze', total: 24},
  {team: 'GBR', medal: 'Bronze', total: 10},
  {team: 'USA', medal: 'Bronze', total: 4}
];

// Resultados parciales / temporales
const countryResults = {};

// Calculamos totales
[
  ...goldMedals,
  ...silverMedals,
  ...bronzeMedals
].map(result => {
    const partialResult = countryResults[result.team];
    countryResults[result.team] = partialResult
      ? partialResult + result.total
      : result.total;
});

// Pasamos los resultados al formato array indicado
const totals = Object
  .keys(countryResults)
  .map(totalResult => (
    {
        team: totalResult,
        totalMedals: countryResults[totalResult]
    }
  )
);

// Mostramos por consola
console.log('Resultado: ', totals);

    If you have any questions, you can use the comments.

    I hope it can help you

    • 1

  2. This solution is super vanilla Javascript. It simply uses a list with indexes the name of the country, and adds up the medals of each country.
    Then, to maintain the object structure, I convert that list (array) to a list of objects {team:'', totalMedals:0}

    metales =[
[{team: 'JOR', medal: 'Gold', total: 1},
{team: 'GBR', medal: 'Gold', total: 64},
{team: 'USA', medal: 'Gold', total: 139}],

[{team: 'JOR', medal: 'Silver', total: 55},
{team: 'GBR', medal: 'Silver', total: 28},
{team: 'USA', medal: 'Silver', total: 25}],

[{team: 'JOR', medal: 'Bronze', total: 24},
{team: 'GBR', medal: 'Bronze', total: 10},
{team: 'USA', medal: 'Bronze', total: 4}],
];

medallas = [];
metales.forEach((valor)=>contarMedallas(valor, medallas));

total = arrayToObject(medallas);
total.sort((a,b)=>(a.total>b.total?-1:1))
console.log(total);

function arrayToObject(meds)
{
   var  total = [];
   for(key in meds){ 
      total.push({team:key, totalMedals: medallas[key]});
   }
   return total;
}

function contarMedallas(equipo, medallas){
    equipo.forEach( (valor) =>{
        if (medallas[valor.team] == undefined){
            medallas[valor.team] = valor.total;
            }
        else{
            medallas[valor.team] += valor.total;
            }    
        })
}
    • 0