Question

How can i check if a child attribute of a json object is null? While firefox recognizes it, Chrome and IE 8 don’t.

I have a json object like this:

centralData.phone.id;
centralData.address.id;
centralData.product.id;
//and many others

And i’d like to check if some of it’s attributes might be null. I’m doing this and it works:

if(centralData.phone != null){
   //Do things
}

But this don’t, since it’s not always i have a StockGroup

if(centralData.product.StockGroup != null){
 //Error
}

So, how can i check if centralData.product.StockGroup is null?

Answer 1

You don’t want to check if it’s null, you want to check if the property exists (it would be undefined in this case). Your check works because you are using == instead of ===, which converts between types (undefined == null, but undefined !== null).

When you want to check for a nested property, you need to check every level. I would recommend to use the in operator, as it checks if the property exists and ignores it’s value.

This does what you want to do:

if("product" in centralData && "StockGroup" in centralData.product){
    …
}