遍历 JSON 对象

Question

I'm having some troubles iterating in a json object. I'm currently saving the table properties of a some web page in a cookie. The value of the cookie is an array of objects which I serialize. The typical value of an array with 2 entries is something like:

cookieValue=["{ "PageID": "1391", "PageSize": "100"}", "{ "PageID": "2341", "PageSize": "50"}"]

My problem is iterating in this array now. I want to be able to check if there is any duplicate entry to update its PageSize (if applicable) or to read it in order to set the page size when a user goes back to the same page.

I've tried this so far:

for (var key in cookieValue) {
   if(cookieValue.hasOwnProperty(key) ){
      console.log(key + " -> " + cookieValue[key]);
   }
}

which give me an output like:

0 -> { "PageID": "1391_tabela", "PageSize": "100"}
1 -> { "PageID": "1391_tabela", "PageSize": "50"}
2 -> { "PageID": "1391_tabela", "PageSize": "10"}

My question is how am i able to access the value of PageID in each entry.

Thanks in advance

Answer 1

I am not sure if I understand you correctly but I think you should just use

cookieValue[key]["PageID"]

together:

for (var key in cookieValue) {
   if(cookieValue.hasOwnProperty(key) ){
      console.log(key + " -> " + cookieValue[key] + " -> " + cookieValue[key]["PageID"]);
   }
}

Answer 2

If you only want to access the value of PageId in each entry, you can view example here :

var cookieValue=[{ "PageID": "1391", "PageSize": "100"}, { "PageID": "2341", "PageSize": "50"}];



for (key in cookieValue) {
alert(cookieValue[key]["PageID"]);
}

JSFIDDLE

Answer 3

Manipulate the data using a javascript array for easier code.

One way that should work for you:

• convert your JSON into a javascript array using:

var mycookieArray = JSON.parse(cookieValue);

• Iterate through it with:

  for(String s : myCookieArray) { console.log(s.PageID); }

Answer 4

It seems that you need to get the object by the PageId. Here is a function

function getPageById(pageId) {
     for (var pageObj in cookieValue) {
          if (pageObj.PageId === pageId)
               return pageObj;
     }
}