Question

这是json示例：

    {
   "kind": "shopping#product",
   "id": "tag:google.com,2010:shopping/products/6582229/17914968800165668776",
   "selfLink": "https://www.googleapis.com/shopping/search/v1/public/products/6582229/gid/17914968800165668776?alt\u003djson",
   "product": {
    "googleId": "17914968800165668776",
    "author": {
     "name": "Red Tag Market",
     "accountId": "6582229"
    },
    "creationTime": "2010-11-30T10:00:00.000Z",
    "modificationTime": "2011-05-01T09:20:00.000Z",
    "country": "US",
    "language": "en",
    "title": "The Fantastic Mr. Fox - BLU-RAY/DVD",
    "description": "Wit.",
    "link": "ht361",
    "condition": "new",
    "gtin": "00024543657552",
    "inventories": [
     {
      "channel": "online",
      "price": 22.51,
      "currency": "USD"
     }
    ],
    "images": [
     {
      "link": "http://208.131.143.232/i/6/3/0/7/6/1/8.jpg",
      "thumbnails": [
       {
        "width": 60,
        "height": 60,
        "link": "hBEevU46OsArJElwIeErF_3E7Zzu12M2eLSvQBdYiMLaRWrI60aF8lHxRqOz-wkx2YJUIVdCrzrEQDWxgcc"
       }
      ]
     }
    ]
   }
  },
  {
   "kind": "shopping#product",
   "id": "tag:google.com,2010:shopping/products/6296724/17894083551590155418",
   "selfLink": "https://www.googleapis.com/shopping/search/v1/public/products/6296724/gid/17894083551590155418?alt\u003djson",
   "product": {
    "googleId": "17894083551590155418",
    "author": {
     "name": "eBay",
     "accountId": "6296724"
    },
    "creationTime": "2011-04-04T00:43:02.000Z",
    "modificationTime": "2011-04-04T00:43:02.000Z",
    "country": "US",
    "language": "en",
    "title": "Fy.",
    "link": "htt530831212&itemid\u003d140530831212&icep_meta_categ_id\u003d11232",
    "condition": "used",
    "gtin": "00024543657552",
    "inventories": [
     {
      "channel": "online",
      "price": 14.99,
      "currency": "USD"
     }
    ],
    "images": [
     {
      "link": "http://i.ebayimg.com/00/%24%28KGrHqYOKkQE1r4Vh1gFBNl4n0t17g%7E%7E_1.JPG?set_id\u003d8800005007",
      "thumbnails": [
       {
        "width": 60,
        "height": 60,
        "link": "http://lh
       }
      ]
     }
    ]
   }
  }

我想要做的是查看data.items[i].product.images[]是否存在。正如你所看到的那样，Images数组不存在于第二个响应中，从而在我尝试将data.items[i].product.images[]用于任何目的的时候杀死了我的javascript。我一直在寻找并且尚未找到解决方案。

编辑：我刚试过这个但仍然没有骰子：

if(data.items[i].product.images !== undefined){
    var image = 'images/inverticon.png';
}else{
    var image = data.items[i].product.images[0].thumbnails[0].link;
}

我没有收到任何错误，脚本停止运行。如果我省略图像代码一切正常，只要返回的JSON有图像[]就可以正常工作。

编辑：这是解决方案：

if(data.items[i].product.images !== undefined){
    var image = data.items[i].product.images[0].thumbnails[0].link;
}else{
    var image = 'images/inverticon.png';
}

Answer 1

if (data.items[i].product.images !== undefined) {
  //do what you will
}

尝试访问不存在的对象的属性将返回undefined。那很可能是你得到的错误？

您是否了解Web浏览器中的Web检查器工具？它们都有一个控制台，可以输出任何错误。如果你检查一下，那么你会看到什么是错的。

您仍在尝试访问该条件语句的else中的images数组，这将导致错误。

应该是这样的，

if(data.items[i].product.images !== undefined){
  var image = data.items[i].product.images[0].thumbnails[0].link;

} else {
  var image = 'images/inverticon.png';
}

'不等于undefined'相当于说'is defined'

Answer 2

有没有理由你不将它解析成PHP数组然后检查？你标记了你的帖子PHP，所以我认为这就是你正在使用的。

$myarray = json_decode($json);
if (isset($myarray->items[0]->product->images)) {
  ...
}

检查JSON中是否存在子数组

2 个答案: