How To Handle json null values in Swift

Question

I am playing With JSON for last two days and facing alot of curious problems and thanks to stack overflow it helps me. This is JSON featured key has two types of String values.

 "featured":"1"

or

"featured": null,

I tried a lot to handle this but failed

Step 1:

 if dict.objectForKey("featured") as? String != nil {
    featured = dict.objectForKey("featured") as? String
    }

Step 2:

    let null = NSNull()
    if dict.objectForKey("featured") as? String != null {
    featured = dict.objectForKey("featured") as? String
    }

Step 3:

    if dict.objectForKey("featured") as? String != "" {
    featured = dict.objectForKey("featured") as? String
    }

but unfortunately can't found solution, you answer will be appreciated.

Answer 1

Try This

func nullToNil(value : AnyObject?) -> AnyObject? {
    if value is NSNull {
        return nil
    } else {
        return value
    }
}

object.feature = nullToNil(dict["feature"])

Here, you can use this method, which will convert null value to nil and wont' cause crash in your app.

You can also use as?

object.feature = dict["feature"] as? NSNumber

Thanks.

Answer 2

Here is a working code, type cast operator(as?) will do the trick here. Null will not be typecasted into String, so the execution will go to failure block.

if let featured = dict["featured"] as? String {
    print("Success")
}
else {
    print("Failure")
}