javascript – How to loop through attributes of a JSON?

Question:

i'm trying to loop through attributes of a json, i'm trying this way

for (var i = 0, length = r.length; i < length; i++) {
   for (var i2 = 0,length = r[i].lenght; i2 < length; i2++ ){
       console.log("teste"+r[i][i2]);
   }
}    

how do i do it correctly?

the Json is coming irregular, because when the service receives a null value from the bank it does not set the field in the json

[
{
    "nome": "Victor Siqueira",
    "login": "victor.justino@spcm.com.br",
    "senha": "ef797c8118f02dfb649607dd5d3f8c7623048c9c063d532cc95c5ed7a898a64f",
    "tempoSessao": 15,
    "acesso": [
        {
            "idTela": "AA00"
        }
    ]
},
{
    "nome": "",
    "tempoSessao": 0,
    "acesso": []
},
{
    "nome": "",
    "login": "as",
    "senha": "1234",
    "tempoSessao": 0,
    "acesso": []
},
{
    "nome": "",
    "login": "as2",
    "senha": "9876",
    "tempoSessao": 0,
    "acesso": []
},
{
    "nome": "",
    "login": "as3",
    "senha": "9876",
    "tempoSessao": 0,
    "acesso": []
},
{
    "nome": "",
    "login": "as4",
    "senha": "a123",
    "tempoSessao": 0,
    "acesso": []
},
{
    "nome": "",
    "login": "as5",
    "senha": "54d5cb2d332dbdb4850293caae4559ce88b65163f1ea5d4e4b3ac49d772ded14",
    "tempoSessao": 0,
    "acesso": []
},
{
    "nome": "",
    "login": "PFernandes",
    "senha": "54d5cb2d332dbdb4850293caae4559ce88b65163f1ea5d4e4b3ac49d772ded14",
    "tempoSessao": 0,
    "acesso": []
},
{
    "nome": "",
    "tempoSessao": 0,
    "acesso": []
},
{
    "nome": "",
    "tempoSessao": 0,
    "acesso": []
},
{
    "nome": "",
    "tempoSessao": 0,
    "acesso": []
},
{
    "nome": "",
    "tempoSessao": 0,
    "acesso": []
},
{
    "nome": "",
    "tempoSessao": 0,
    "acesso": []
},
{
    "nome": "",
    "tempoSessao": 0,
    "acesso": []
},
{
    "nome": "",
    "tempoSessao": 0,
    "acesso": []
},
{
    "nome": "",
    "tempoSessao": 0,
    "acesso": []
},
{
    "nome": "",
    "tempoSessao": 0,
    "acesso": []
}

]

Answer:

I think the best way is for you to work with objects.

If you assign your JSON string to an object you will be able to access it more easily.

var arrayJson = JSON.parse("tua string JSON");
arrayJson.forEach(function(pessoa){
  var acesso = pessoa.acesso;
  acesso.forEach(function(acesso)){
    if (acesso != null)
      //acesso.idTela - para acessar a propriedade pelo nome
  }
})

I don't know if I was clear, but I'll answer any questions.