javascript - 无法在 json 对象内部找到

Question

我有一个代码来迭代代码，并希望通过比较类别来获得产品项目，例如:如果类别是“汽车”，那么该数组内的产品应该使用索引而不是名称进行迭代

html

<ul class="menulist"></ul>
<div class="content"></div>

js

var jsonData;
$(document).ready(function () {
    $.ajax({
        url: "product.json",
        dataType: "json",
        error: function () {

        },
        success: getData

    });

    function getData(data) {
        alert(data)
        for (i = 0; i < data.length; i++) {


            var menulistdata = data[i].category,
                menulist = '<li class="" data-att="' + menulistdata + '">' + menulistdata + '</li>'
            $(".menulist").append(menulist);
        }


        $('.menulist li').on('click', function () {

            var list = $(this).text();

            for (i = 0; i < data.length; i++) {
                alert(i)

                var productData = data[i].products;
                if (data[i].category == list) {
                    $(".content").append(productData.BMG[i].image + productData.BMG[i].date + productData.BMG[i].size);
                }



            }
        })
    }

});

json

[
    {
        "category":"car",
        "products": {
            "BMG" : [{
                "image" : "images/cars/BMW.jpg",
                "date": "5-May-2015",
                "type": "JPGE image",
                "size": "1132 KB"
            }],

            "verna":[{
                "image" : "images/cars/Verna.jpg",
                "date": "5-May-2015",
                "type": "JPGE image",
                "size": "1132 KB"
            }]
        }
    },

    {
        "category":"Nature",
        "products": {
            "Nature Mood At Night" : [{
                "image" : "images/nature/Night.jpg",
                "date": "5-May-2015",
                "type": "JPGE image",
                "size": "1132 KB"
            }],

            "Snowfall on Hut":[{
                "image" : "images/nature/Hut.jpg",
                "date": "5-May-2015",
                "type": "JPGE image",
                "size": "1132 KB"
            }]
        }
    }
]

Working Fiddle

Answer 1

data[0].products 是对象类型 - 您不能通过索引迭代对象，只能通过命名键迭代。使用for..in 语句迭代对象。

for( var key in data[0].products ) {
    console.log( data[0].products[key] );
}

参见:https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/for...in