我有这个集合：https://graph.facebook.com/2playcz/albums
此集合包含8个ID。如何使用javascript获取此集合的总计数ID？ （总计= 8 ）
来源：
{
"data": [
{
"id": "201936779932071",
"from": {
"name": "2play.cz - Tenisov\u00e1 \u0161kola",
"category": "Sports league",
"id": "190320081093741"
},
"name": "Tr\u00e9ninky",
"link": "https://www.facebook.com/album.php?fbid=201936779932071&id=190320081093741&aid=41883",
"cover_photo": "201937046598711",
"count": 8,
"type": "normal",
"created_time": "2012-07-02T09:33:43+0000",
"updated_time": "2012-09-15T12:05:44+0000",
"can_upload": false,
"likes": {
"data": [
{
"id": "1788805921",
"name": "Edita Nov\u00e1"
},
{
"id": "100001449904219",
"name": "Mirka Brani\u0161ov\u00e1"
}
],
"paging": {
"next": "https://graph.facebook.com/201936779932071/likes?limit=25&offset=25&__after_id=100001449904219"
}
}
},
{
"id": "205206429605106",
"from": {
"name": "2play.cz - Tenisov\u00e1 \u0161kola",
"category": "Sports league",
"id": "190320081093741"
},
"name": "Turnaje a akce",
"link": "https://www.facebook.com/album.php?fbid=205206429605106&id=190320081093741&aid=42900",
"cover_photo": "205208716271544",
"count": 14,
"type": "normal",
"created_time": "2012-07-10T19:36:53+0000",
"updated_time": "2012-09-15T12:04:05+0000",
"can_upload": false
},
{
"id": "221784994613916",
"from": {
"name": "2play.cz - Tenisov\u00e1 \u0161kola",
"category": "Sports league",
"id": "190320081093741"
},
"name": "Tenisova \u0161kolka 2play",
"description": "Tenisov\u00e1 \u0161kolka 2play",
"link": "https://www.facebook.com/album.php?fbid=221784994613916&id=190320081093741&aid=49379",
"cover_photo": "221785024613913",
"count": 9,
"type": "normal",
"created_time": "2012-08-31T11:19:59+0000",
"updated_time": "2012-09-14T15:17:53+0000",
"can_upload": false
},
{
"id": "203405996451816",
"from": {
"name": "2play.cz - Tenisov\u00e1 \u0161kola",
"category": "Sports league",
"id": "190320081093741"
},
"name": "Webov\u00e9 fotografie - Logo",
"link": "https://www.facebook.com/album.php?fbid=203405996451816&id=190320081093741&aid=42285",
"cover_photo": "203406586451757",
"count": 11,
"type": "normal",
"created_time": "2012-07-05T10:12:40+0000",
"updated_time": "2012-09-14T15:16:40+0000",
"can_upload": false
},
{
"id": "190332361092513",
"from": {
"name": "2play.cz - Tenisov\u00e1 \u0161kola",
"category": "Sports league",
"id": "190320081093741"
},
"name": "Cover Photos",
"link": "https://www.facebook.com/album.php?fbid=190332361092513&id=190320081093741&aid=39232",
"cover_photo": "225939404198475",
"count": 2,
"type": "normal",
"created_time": "2012-06-09T13:52:38+0000",
"updated_time": "2012-09-12T18:15:51+0000",
"can_upload": false
},
{
"id": "190802884378794",
"from": {
"name": "2play.cz - Tenisov\u00e1 \u0161kola",
"category": "Sports league",
"id": "190320081093741"
},
"name": "Wall Photos",
"link": "https://www.facebook.com/album.php?fbid=190802884378794&id=190320081093741&aid=39324",
"cover_photo": "190802891045460",
"count": 2,
"type": "wall",
"created_time": "2012-06-10T13:19:48+0000",
"updated_time": "2012-07-17T17:16:19+0000",
"can_upload": false
},
{
"id": "205207126271703",
"from": {
"name": "2play.cz - Tenisov\u00e1 \u0161kola",
"category": "Sports league",
"id": "190320081093741"
},
"name": "Ostatn\u00ed",
"link": "https://www.facebook.com/album.php?fbid=205207126271703&id=190320081093741&aid=42902",
"cover_photo": "205209679604781",
"count": 4,
"type": "normal",
"created_time": "2012-07-10T19:40:05+0000",
"updated_time": "2012-07-16T14:47:16+0000",
"can_upload": false,
"likes": {
"data": [
{
"id": "100001449904219",
"name": "Mirka Brani\u0161ov\u00e1"
}
],
"paging": {
"next": "https://graph.facebook.com/205207126271703/likes?limit=25&offset=25&__after_id=100001449904219"
}
}
},
{
"id": "190320914426991",
"from": {
"name": "2play.cz - Tenisov\u00e1 \u0161kola",
"category": "Sports league",
"id": "190320081093741"
},
"name": "Profile Pictures",
"link": "https://www.facebook.com/album.php?fbid=190320914426991&id=190320081093741&aid=39224",
"cover_photo": "190327474426335",
"count": 1,
"type": "profile",
"created_time": "2012-06-09T13:29:16+0000",
"updated_time": "2012-06-09T13:43:08+0000",
"can_upload": false
},
{
"id": "190322704426812",
"from": {
"name": "2play.cz - Tenisov\u00e1 \u0161kola",
"category": "Sports league",
"id": "190320081093741"
},
"name": "Logo",
"description": "Loga spole\u010dnosti",
"link": "https://www.facebook.com/album.php?fbid=190322704426812&id=190320081093741&aid=39225",
"type": "normal",
"created_time": "2012-06-09T13:34:09+0000",
"updated_time": "2012-07-05T10:16:58+0000",
"can_upload": false
}
]
}
答案 0 :(得分：1)
如果您指的是data数组中的项目数，则只有data.length。
答案 1 :(得分：0)
首先， 9 ID。如果要计算数组中元素的数量，则有一个内置属性length。因此，如果您的对象被调用x，则可以通过访问x.data.length来检索数据的长度。
另一方面，如果你想计算唯一ID的数量（ID应该是唯一的，但如果你真的想要），你必须手动迭代数组并计算它们：
var countIds = function (arr) {
var uniqueIds = {}, num = 0;
if (!arr.data) return false;
arr.data.forEach(function (val, i) {
if (typeof uniqueIds[val.id] === "undefined") {
++num;
uniqueIds[val.id] = true;
}
});
return num;
};