Question

所以，我有一个像这样的“数据库”：

var db = {
  cars: [
    {brand: 'x', color: 'blue'},
    {brand: 'y', color: 'red'}
  ],
  pcs: {
    allInOne: [
      {brand: 'z', ram: '4gb'},
      {brand: 'v', ram: '8gb'}
    ],
    desktop: [
      {brand: 'a', ram: '16gb'},
      {brand: 'b', ram: '2gb'}
    ]
  }
}

如您所见，可以有子类别。当然，我的“数据库”比那个更重要。但这个概念是一样的。我需要从对象中获取3个随机项，并使用类别存储它们，如果存在则存储子类别，如下所示：

var random = [
  {categorie: 'cars', subcategorie: null, product: {...}},
  {categorie: 'cars', subcategorie: null, product: {...}},
  {categorie: 'pcs', subcategorie: 'desktop', product: {...}}
]

另外，我需要他们不重复。我怎样才能做到这一点？提前谢谢！

Answer 1

＆＃13;

function getRandom(db, num) {
  // FIRST: get an array of all the products with their categories and subcategories
  var arr = []; // the array
  Object.keys(db).forEach(function(k) { // for each key (category) in db
    if(db[k] instanceof Array) {        // if the category has no subcategories (if it's an array)
      db[k].forEach(function(p) {       // then for each product p add an entry with the category k, sucategory null, and the product p
        arr.push({categorie: k, subcategorie: null, product: p});
      });
    }
    else {                                      // if this caegory has subcategories
      Object.keys(db[k]).forEach(function(sk) { // then for each sucategory
        db[k][sk].forEach(function(p) {         // add the product with category k, subcategory sk, and product p
          arr.push({categorie: k, subcategorie: sk, product: p});
        })
      });
    }
  });

  // SECOND: get num random entries from the array arr
  var res = [];
  while(arr.length && num) { // while there is products in the array and num is not yet acheived
    var index = Math.floor(Math.random() * arr.length); // get a random index
    res.push(arr.splice(index, 1)[0]); // remove the item from arr and push it into res (splice returns an array, see the docs)
    num--;
  }
  return res;
}


var db = {cars: [{brand: 'x', color: 'blue'},{brand: 'y', color: 'red'}],pcs: {allInOne: [{brand: 'z', ram: '4gb'},{brand: 'v', ram: '8gb'}],desktop: [{brand: 'a', ram: '16gb'},{brand: 'b', ram: '2gb'}]}};

console.log(getRandom(db, 3));

＆＃13;

从嵌套对象中获取10个随机项，不重复

1 个答案: