select into JSON

Question

suite à ma question

il est posible de sélectionner des valeurs dans mon objet JSON que cela représente pour la liste des écoles distinctes où aaa a étudié

objet JSON ressembler à ceci

[{ » nom ":" aaa "," 0 ":" aaa "," ville ":" paris "," 1 ":" paris "," école ":" gtdzh "," 2 ":" gtdzh "}, {" nom ":" bbb "," 0 ":" bbb "," ville ":" berlin "," 1 ":" berlin "," école ":" gdezh "," 2 ":" gdezh "}, {" nom ":" ccc "," 0 ":" ccc "," ville ":" new york "," 1 ":" new york "," école ":" asdzh "," 2 ":" asdzh "}, {"name": "aaa", "0": "aaa", "ville": "sidney", "1": "sidney", "école": "gtdcv", "2": "gtdcv"}, {"nom": "bbb", "0": "bbb", "ville": "paris", "1": "paris", "école": "gtdzh", "2": "gtdzh"}]

merci pour votre aide

Answer 1

Si tous les noms peuvent être garantis d'être unique, vous pouvez faire quelque chose comme ceci:

var data_array = [ 
{"name":"aaa","0":"aaa","city":"paris","1":"paris","school":"gtdzh","2":"gtdzh"}, 
{"name":"bbb","0":"bbb","city":"berlin","1":"berlin","school":"gdezh","2":"gdezh"}, 
{"name":"ccc","0":"ccc","city":"new york","1":"new york","school":"asdzh","2":"asdzh"}, 
{"name":"aaa","0":"aaa","city":"sidney","1":"sidney","school":"gtdcv","2":"gtdcv"}, 
{"name":"bbb","0":"bbb","city":"paris","1":"paris","school":"gtdzh","2":"gtdzh"} 
]; 

var l = data_array.length; 
var i = 0 

// We will use dict to store our output 
var dict = {}; 

// Loop over the entire array 
while (i < l) { 
    // Grab references to everything we need 
    var name = data_array[i].name; 
    var city = data_array[i].city; 

    // If we haven't seen this person before, add them to the dict 
    if (! Object.prototype.hasOwnProperty.call(dict, name)) { 
     dict[name] = {}; 
    } 

    // Similarly, if we haven't heard of them studying in this city yet 
    // add that city to the "dictionary" of cities they've studied in 
    // and set the count of times they have studied in that city to 1. 
    if (! Object.prototype.hasOwnProperty.call(dict[name], city)) { 
     dict[name][city] = 1; 
    // Otherwise, increment the number of times they have studied in that city. 
    } else { 
     dict[name][city] += 1; 
    } 
    i++; 
} 

Le le résultat final ressemblera à quelque chose comme ceci:

dict = { 
    "aaa": { 
     "paris": 1, 
     "sidney": 1 
    }, 
    "bbb": { 
     "berlin": 1, 
     "paris": 1 
    }, 
    "ccc": { 
     "new york": 1 
    } 
}; 

Bien sûr, il y a de meilleures façons d'y parvenir si vous faites ce genre de chose à plusieurs reprises - tout de changer la façon dont les données sont envoyées du serveur à la construction ou à l'aide de bibliothèques auxiliaires comme Underscore pour faire ce genre de données-munging. Il y a aussi quelques implémentations de bases de données Javascript, mais je n'ai travaillé avec aucune d'entre elles donc je ne peux rien recommander à cet égard.