Locate id within json array[]

Question

Good night!

I’m having a problem locating array by square bracket case.

I’m trying to get the data from "Stats". But its only reference is "accountId" or "summonerName". To get the reference of "Stats" need to get the id "participantId" that’s inside the "participantIdentities".

But my problem is I’m not getting the id "participantId".

JSON Base - Example

{  
   "gameId":1189987226,
   "participantIdentities":[  
      {  
         "player":{  
            "summonerName":"Khal Droggo",
            "accountId":1595535
         },
         "participantId":1
      },
      {  
         "player":{  
            "summonerName":"Lefetos",
            "accountId":211703728
         },
         "participantId":2
      }
   ],
   "participants":[  
      {  
         "stats":{  
            "champLevel":16,
            "participantId":1
         },
         "participantId":1
      },
      {  
         "stats":{  
            "champLevel":15,
            "participantId":2
         },
         "participantId":2
      }
   ]
}

I’m using javascript language.

function callback(andress, fn){
    $.ajax({
        url: andress,
        type: 'GET',
        dataType: 'json',
        error: function(){},
        success: fn
    });
}

function stats(accountId){
    callback('https://api.myjson.com/bins/1ew27p', function(retorno) {
        var obj = retorno.participantIdentities;
        Object.keys(obj).forEach(function(prop) {
            if (obj[prop].accountId == accountId) {
                document.write(obj[prop].participantId);
            }
        });
    });
}

stats(211703728);

Answer 1

Based on the answer to a question put to the Soen

The best solution is to use the method grep of jQuery.

var participante = $.grep( obj, function( n, i ) {
    return n.player.accountId===accountId;
});

To recover the value of participantId

participante[0].participantId

Getting your code like this.

function callback(andress, fn){
    $.ajax({
        url: andress,
        type: 'GET',
        dataType: 'json',
        error: function(){},
        success: fn
    });
}

function stats(accountId){
    callback('https://api.myjson.com/bins/1ew27p', function(retorno) {
      var obj = retorno.participantIdentities;
      var participante = $.grep( obj, function( n, i ) {
        return n.player.accountId===accountId;
      });
      console.log(participante[0].participantId);
    });
}

stats(211703728);

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>

Answer 2

The logic you’re using to find the player works, only access to the field accountId is that it is not correct, this obj[prop].accountId.

Makes a foreach in participantIdentities means that each object of that foreach will be something like:

{  
     "player":{  
        "summonerName":"Khal Droggo",
        "accountId":1595535
     },
     "participantId":1
}

Which means to access the accountId will have to do .player.accountId instead of .accountId directly as you have.

So just change the if that has to:

if (obj[prop].player.accountId == accountId) { //agora .player.accountId

If player may not exist then it is appropriate to confirm whether it exists using the function hasOwnProperty what would turn out like this:

if (obj[prop].hasOwnProperty("player") && obj[prop].player.accountId == accountId) {

Example:

function callback(andress, fn){
    $.ajax({
        url: andress,
        type: 'GET',
        dataType: 'json',
        error: function(){},
        success: fn
    });
}

function stats(accountId){
    callback('https://api.myjson.com/bins/1ew27p', function(retorno) {
        var obj = retorno.participantIdentities;
        Object.keys(obj).forEach(function(prop) {
            if (obj[prop].hasOwnProperty("player") && obj[prop].player.accountId == accountId) { //if alterado aqui
                console.log(`Achou jogador ${obj[prop].player.summonerName} com participantId de ${obj[prop].participantId}`);
                return;//se achou não ve mais nenhum
            }
        });
    });
}

stats(211703728);

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>