JavaScript如何根据属性过滤对象数组？

Question

我有以下JavaScript数组的房地产主页对象：

var json = {
    'homes': [{
            "home_id": "1",
            "price": "925",
            "sqft": "1100",
            "num_of_beds": "2",
            "num_of_baths": "2.0",
        }, {
            "home_id": "2",
            "price": "1425",
            "sqft": "1900",
            "num_of_beds": "4",
            "num_of_baths": "2.5",
        },
        // ... (more homes) ...     
    ]
}

var xmlhttp = eval('(' + json + ')');
homes = xmlhttp.homes;

我想做的是能够对对象执行过滤，以返回“家庭”对象的子集。

例如，我想根据能够过滤：price，sqft，num_of_beds，和num_of_baths。

如何在JavaScript中执行类似下面的伪代码的操作：

var newArray = homes.filter(
    price <= 1000 & 
    sqft >= 500 & 
    num_of_beds >=2 & 
    num_of_baths >= 2.5 );

注意，语法不必与上面完全相同。这只是一个例子。

Answer 1

您可以使用以下Array.prototype.filter方法：

var newArray = homes.filter(function (el) {
  return el.price <= 1000 &&
         el.sqft >= 500 &&
         el.num_of_beds >=2 &&
         el.num_of_baths >= 2.5;
});

现场示例：

var obj = {

    'homes': [{

            "home_id": "1",

            "price": "925",

            "sqft": "1100",

            "num_of_beds": "2",

            "num_of_baths": "2.0",

        }, {

            "home_id": "2",

            "price": "1425",

            "sqft": "1900",

            "num_of_beds": "4",

            "num_of_baths": "2.5",

        },

        // ... (more homes) ...

    ]

};

// (Note that because `price` and such are given as strings in your object,

// the below relies on the fact that <= and >= with a string and number

// will coerce the string to a number before comparing.)

var newArray = obj.homes.filter(function (el) {

  return el.price <= 1000 &&

         el.sqft >= 500 &&

         el.num_of_beds >= 2 &&

         el.num_of_baths >= 1.5; // Changed this so a home would match

});

console.log(newArray);

此方法是新ECMAScript 5th Edition标准的一部分，几乎可以在所有现代浏览器中找到。

对于IE，您可以包括以下兼容性方法：

if (!Array.prototype.filter) {
  Array.prototype.filter = function(fun /*, thisp*/) {
    var len = this.length >>> 0;
    if (typeof fun != "function")
      throw new TypeError();

    var res = [];
    var thisp = arguments[1];
    for (var i = 0; i < len; i++) {
      if (i in this) {
        var val = this[i];
        if (fun.call(thisp, val, i, this))
          res.push(val);
      }
    }
    return res;
  };
}