Check if parsed json is NSNULL

Question

I am parsing a JSON response and trying to check if one of my keys is null. How would I go about this? I have the following:

var routingNumber = (dic.value(forKey: "result") as! NSDictionary).value(forKey: "routingNumber") as! String

and this returns:

Could not cast value of type 'NSNull' (0x107d238c8) to 'NSString' (0x107329c40).

How would I check if the value is NSNULL?

if( something != NSNULL){
    do something
}else{
    do something else
}

if let routingNumber = (dic["result"] as? [String: Any])?["routingNumber"] as? String { } — Suen, Feb 23 '17 at 05:23
Do not use `NSDictionary` in Swift. Use a Swift dictionary. Do not use `value(forKey:)` to get a value unless you have a specific reason to be using KVC (which you don't have in this case). — rmaddy, Feb 23 '17 at 05:59

score 11 · Answer 1 · edited Feb 23 '17 at 05:49

11

You can extract value from dic like this.

if let value = (dict["key"] as? String) 
{ 
  //NOT NULL
} 
else 
{
   //NULL
}

edited Feb 23 '17 at 05:49

Rocky Balboa

784
10
25

answered Feb 23 '17 at 05:24

Amit Singh

172
1
12

The parentheses are not needed. – rmaddy Feb 23 '17 at 05:59
1

Does this make sure that the value for `dict["key"]` isn't nil AND also a `String` (not other types)? – Heuristic Jun 16 '17 at 05:40

score 6 · Answer 2 · edited Feb 23 '17 at 07:20

create below function

func isNsnullOrNil(object : AnyObject?) -> Bool
{
    if (object is NSNull) || (object == nil)
    {
        return true
    }
    else
    {
        return false
    }
}

call function where you want to check for null or nil value

if isNsnullOrNil((dic.value(forKey: "result") as! NSDictionary).value(forKey: "routingNumber"))
{
    print("object is null or nil")
}
else
{
    print("object is not  null or nil")
}

Brandon A · Answer 3 · 2017-02-23T05:34:43.470

0

I had this same problem once.

CHECK FOR IF NSNULL

if let result = dic["result"] as? NSDictionary {
    // There is a dictionary

    if let routingNumber = result["routingNumber"] as? String {
         // There is a routingNumber
    }
    else if let routingNumber = result["routingNumber"] as? NSNull {
         // There is routingNumber but Null
    }
    else {
        // No routingNumber
    }
}

That should do the trick.

edited Feb 23 '17 at 05:34

answered Feb 23 '17 at 05:27

Brandon A

8,153
3
42
77

Why use `NSDictionary`? Use a Swift dictionary. – rmaddy Feb 23 '17 at 06:07
1

user2423476's question used `NSDictionary`. – Brandon A Feb 23 '17 at 06:19

score 0 · Answer 4 · edited Feb 23 '17 at 06:14

0

if let result = dict["result"] as? [String:Any], let routingNumber = result["routingNumber"] as? String { 
    print("the routingNumber is \(routingNumber)")
} else { 
    print("nil") 
}

edited Feb 23 '17 at 06:14

Rajesh73

342
1
6
16

answered Feb 23 '17 at 05:31

Ram

961
6
14

Check if parsed json is NSNULL

4 Answers4