我的函数是以下列格式返回JSON数据：
"searchResult":[
{
"@count":"100",
"item":[
{
"itemId":[
"151258132867"
],
"title":[
"Apple iPhone 4 - clean esn - Black (Verizon) Smartphone"
],
"globalId":[
"EBAY-US"
],
"primaryCategory":[
{
"categoryId":[
"9355"
],
"categoryName":[
"Cell Phones & Smartphones"
]
}
],
"galleryURL":[
"http:\/\/thumbs4.ebaystatic.com\/m\/mGwHzpyvkph9-nU12sCspxw\/140.jpg"
],
"viewItemURL":[
"http:\/\/www.ebay.com\/itm\/Apple-iPhone-4-clean-esn-Black-Verizon-Smartphone-\/151258132867?pt=Cell_Phones"
],
"productId":[
{
"@type":"ReferenceID",
"__value__":"101787954"
}
],
"paymentMethod":[
"PayPal"
],
"autoPay":[
"false"
],
"postalCode":[
"93905"
],
"location":[
"Salinas,CA,USA"
],
"country":[
"US"
],
"shippingInfo":[
{
"shippingServiceCost":[
{
"@currencyId":"USD",
"__value__":"0.0"
}
],
"shippingType":[
"Free"
],
"shipToLocations":[
"US"
],
"expeditedShipping":[
"true"
],
"oneDayShippingAvailable":[
"false"
],
"handlingTime":[
"2"
]
}
],
"sellingStatus":[
{
"currentPrice":[
{
"@currencyId":"USD",
"__value__":"96.0"
}
],
"convertedCurrentPrice":[
{
"@currencyId":"USD",
"__value__":"96.0"
}
],
"bidCount":[
"17"
],
"sellingState":[
"Active"
],
"timeLeft":[
"P0DT0H0M11S"
]
}
],
"listingInfo":[
{
"bestOfferEnabled":[
"false"
],
"buyItNowAvailable":[
"false"
],
"startTime":[
"2014-03-19T18:29:51.000Z"
],
"endTime":[
"2014-03-26T18:29:51.000Z"
],
"listingType":[
"Auction"
],
"gift":[
"false"
]
}
],
"returnsAccepted":[
"false"
],
"condition":[
{
"conditionId":[
"3000"
],
"conditionDisplayName":[
"Used"
]
}
],
"isMultiVariationListing":[
"false"
],
"topRatedListing":[
"false"
]
},
{
"itemId":[
"360810145746"
],
"title":[
"U Apple iPhone 3GS - 8GB - Black (FACTORY UNLOCKED) Smartphone (C)"
],
"globalId":[
"EBAY-US"
],
"subtitle":[
"****USA SELLER*****FAST SHIPPING*****TOP SELLER****"
],
"primaryCategory":[
{
"categoryId":[
"9355"
],
"categoryName":[
"Cell Phones & Smartphones"
]
}
],
"galleryURL":[
"http:\/\/thumbs3.ebaystatic.com\/m\/mQGXy5hucEtqk6inUKFu67g\/140.jpg"
],
"viewItemURL":[
"http:\/\/www.ebay.com\/itm\/U-Apple-iPhone-3GS-8GB-Black-FACTORY-UNLOCKED-Smartphone-C-\/360810145746?pt=Cell_Phones"
],
"productId":[
{
"@type":"ReferenceID",
"__value__":"99984545"
}
],
"paymentMethod":[
"PayPal"
],
"autoPay":[
"true"
],
"postalCode":[
"10001"
],
"location":[
"New York,NY,USA"
],
"country":[
"US"
],
"shippingInfo":[
{
"shippingServiceCost":[
{
"@currencyId":"USD",
"__value__":"0.0"
}
],
"shippingType":[
"Free"
],
"shipToLocations":[
"US",
"CA",
"GB",
"AU",
"FR",
"HK",
"MT",
"IE",
"IL",
"NZ",
"PH",
"SG"
],
"expeditedShipping":[
"true"
],
"oneDayShippingAvailable":[
"false"
],
"handlingTime":[
"1"
]
}
],
"sellingStatus":[
{
"currentPrice":[
{
"@currencyId":"USD",
"__value__":"84.95"
}
],
"convertedCurrentPrice":[
{
"@currencyId":"USD",
"__value__":"84.95"
}
],
"sellingState":[
"Active"
],
"timeLeft":[
"P12DT0H9M11S"
]
}
],
"listingInfo":[
{
"bestOfferEnabled":[
"false"
],
"buyItNowAvailable":[
"false"
],
"startTime":[
"2013-12-08T18:33:51.000Z"
],
"endTime":[
"2014-04-07T18:38:51.000Z"
],
"listingType":[
"StoreInventory"
],
"gift":[
"false"
]
}
],
"returnsAccepted":[
"true"
],
"condition":[
{
"conditionId":[
"3000"
],
"conditionDisplayName":[
"Used"
]
}
],
"isMultiVariationListing":[
"false"
],
"discountPriceInfo":[
{
"originalRetailPrice":[
{
"@currencyId":"USD",
"__value__":"449.0"
}
],
"pricingTreatment":[
"STP"
],
"soldOnEbay":[
"false"
],
"soldOffEbay":[
"false"
]
}
],
"topRatedListing":[
"true"
]
}
等。每个项目属于某个categoryId。例如，在这种情况下，我想要做的是计算每个唯一categoryId显示的次数，然后将前两个categoryId存储在一个数组中。我认为这可以通过For循环完成，但我不确定如何设置。任何帮助表示赞赏，谢谢！
答案 0 :(得分：0)
循环浏览searchResult.item并将categoryId存储在<CategoryID, NumOccurences>
var categoryIds = {};
for (var i = 0, l = searchResult.item.length; i < l; i++) {
var categoryId = searchResult.item[i].primaryCategory.categoryId;
categoryIds[categoryId] = ++(categoryIds[categoryId] || 0);
}
// console.log(categoryIds);
// > { '1234': 1, '2345': 2, ... }
答案 1 :(得分：0)
这应该有效：
var o = {};
data.searchResult[0].item.forEach(function(item) {
var id = item.primaryCategory[0].categoryId;
if (o[id]) o[id]++;
else o[id] = 1;
});
var top2 = Object.keys(o).sort(function(a, b) { return o[b]-o[a]; }).slice(0, 2);
console.log('Top two categories: ' + top2.join(', '));