這是我的JSON代碼。我將這個json存儲在一個數組中。如何使用Javascript讀取JSON數組以獲取值(如果存在)
{
"kind": "urlshortener#url",
"id": "http://goo.gl/2FIrtF",
"longUrl": "http://hike.com/?utm_source=facebook",
"status": "OK",
"created": "2015-09-22T13:45:53.645+00:00",
"analytics": {
"allTime": {
"shortUrlClicks": "1",
"longUrlClicks": "1",
"referrers": [
{
"count": "1",
"id": "unknown"
}
],
"countries": [
{
"count": "1",
"id": "IN"
}
],
"browsers": [
{
"count": "1",
"id": "Chrome"
}
],
"platforms": [
{
"count": "1",
"id": "Macintosh"
}
]
},
"month": {
"shortUrlClicks": "1",
"longUrlClicks": "1",
"referrers": [
{
"count": "1",
"id": "unknown"
}
],
"countries": [
{
"count": "1",
"id": "IN"
}
],
"browsers": [
{
"count": "1",
"id": "Chrome"
}
],
"platforms": [
{
"count": "1",
"id": "Macintosh"
}
]
},
"week": {
"shortUrlClicks": "1",
"longUrlClicks": "1",
"referrers": [
{
"count": "1",
"id": "unknown"
}
],
"countries": [
{
"count": "1",
"id": "IN"
}
],
"browsers": [
{
"count": "1",
"id": "Chrome"
}
],
"platforms": [
{
"count": "1",
"id": "Macintosh"
}
]
},
"day": {
"shortUrlClicks": "0",
"longUrlClicks": "0"
},
"twoHours": {
"shortUrlClicks": "0",
"longUrlClicks": "0"
}
},
"result": {
"kind": "urlshortener#url",
"id": "http://goo.gl/2FIuvF",
"longUrl": "http://hike.com/?utm_source=facebook",
"status": "OK",
"created": "2015-09-22T13:45:53.645+00:00",
"analytics": {
"allTime": {
"shortUrlClicks": "1",
"longUrlClicks": "1",
"referrers": [
{
"count": "1",
"id": "unknown"
}
],
"countries": [
{
"count": "1",
"id": "IN"
}
],
"browsers": [
{
"count": "1",
"id": "Chrome"
}
],
"platforms": [
{
"count": "1",
"id": "Macintosh"
}
]
},
"month": {
"shortUrlClicks": "1",
"longUrlClicks": "1",
"referrers": [
{
"count": "1",
"id": "unknown"
}
],
"countries": [
{
"count": "1",
"id": "IN"
}
],
"browsers": [
{
"count": "1",
"id": "Chrome"
}
],
"platforms": [
{
"count": "1",
"id": "Macintosh"
}
]
},
"week": {
"shortUrlClicks": "1",
"longUrlClicks": "1",
"referrers": [
{
"count": "1",
"id": "unknown"
}
],
"countries": [
{
"count": "1",
"id": "IN"
}
],
"browsers": [
{
"count": "1",
"id": "Chrome"
}
],
"platforms": [
{
"count": "1",
"id": "Macintosh"
}
]
},
"day": {
"shortUrlClicks": "0",
"longUrlClicks": "0"
},
"twoHours": {
"shortUrlClicks": "0",
"longUrlClicks": "0"
}
}
}
}
在上面的JSON,我們怎麼能得到分析的存在 - >日 - >國家?
我想知道這些國家是否在一天之內存在,如果不存在,則顯示一些價值。如果它在那裏,它將嘗試獲取特定國家的計數。
我試圖從最後5小時沒有任何運氣。
if(arr.analytics.day.countries !== undefined) {
function thingscount(arr, platf) {
var x = arr.analytics.day.countries.map(function(el) {
return (platf.indexOf(el.id) != -1) ? parseInt(el.count) : 0; });
var count = 0;
for (var i = 0; i < x.length; i++) count += x[i];
return count;
}
var one = thingscount(arr, ["US"]);
}else{
var one = 0;
}
上面的代碼工作,如果有在日國家罰款,但有時,在我的JSON就沒有平臺的一部分,在這種情況下,它給了我
Uncaught TypeError: Cannot read property 'map' of undefined
我需要一種方法檢查平臺是否存在,是否需要計數,如果沒有給變量賦予其他值。
UPDATE:
我用下面的代碼這獲得的計數。
當它具有IN鍵和值時,它會給出結果。但是當它沒有IN鍵時,它顯示'undefined count'錯誤。
var month_inclicks = arr.analytics.month.countries.filter(function(el) { return el.id == "IN"; })[0].count;
我們如何可以設置默認值,如果我們正在尋找的關鍵是不存在?
這不是JSON。 http://jsonlint.com/ – Quentin
對不起,有效的JSON更新。 – Anvy