javascript object undefined error

Question

I have Dynamic AJAX JSON Response object Data variable

 var Data = {"categories":
    [
      {"Id":"2","CategoryName":"Womens"},
      {"Id":"3","CategoryName":"Mens"},{"Id":"4","CategoryName":"Kids"},
      {"Id":"5","CategoryName":"Home"},{"Id":"6","CategoryName":"Health and Beauty"},
      {"Id":"7","CategoryName":"Seasonal Events"},{"Id":"10","CategoryName":"Model Shots"},
      {"Id":"11","CategoryName":"Product Shots"},      
      {"Id":"12","CategoryName":"Accessories"},
      {"Id":"13","CategoryName":"Tops"},{"Id":"14","CategoryName":"Spuds"},
      {"Id":"15","CategoryName":"EVIAN"}
     ],
         "brands_cat":{
             "_bandCount":{"171": "BrandId" : "171", "ArchiveName": "HP",     
             "img_from_archive":"7"}
                      }
    }
  };

When i used in loop and check undefined, works fine

for(var i in Data.categories){
   if(typeof Data.categories[i] == 'undefined'){
       alert(i+"Cat undefined");
   }
}

But when i used typeof to check undefined,

for(var i in Data.categories){
       if(typeof Data.brands_cat._catCount[i].total == 'undefined'){
           alert(i+"Cat total undefined");
       }
    }

And it gave error

TypeError: Data.brands_cat._catCount is undefined

Is it possible to check multilevel JSON object undefined with typeof keyword

thefourtheye · Accepted Answer · 2014-01-11 13:53:17Z

1

There is no _catCount in brands_cat. So, change it like this

if (Data.brands_cat.hasOwnProperty("_catCount")) {
    for (var i in Data.brands_cat._catCount) {
        if(typeof Data.brands_cat._catCount[i].total == 'undefined') {

This code will iterate through _catCount only if it is found

answered Jan 11, 2014 at 13:53

thefourtheye

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1 Comment

Girish Over a year ago

There might have _catCount, it is category items count, so how i can prevent from error

xspydr · Accepted Answer · 2014-01-11 13:53:16Z

0

Within the example object you gave brands_cat does not always exist. When you iterate you need to check for the existence of that first prior to checking anything further down the object tree.

answered Jan 11, 2014 at 13:53

xspydr

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