Chris Chris - 1 year ago 68
iOS Question

Checking a null value in Objective-C that has been returned from a JSON string

I have a JSON object that is coming from a webserver.

The log is something like this:


Note the Telephone is coming in as null if the user doesn't enter one.

When assigning this value to a
, in the
it's coming out as

I am assigning the string like this:

NSString *tel = [jsonDictionary valueForKey:@"Telephone"];

What is the correct way to check this
value? It's preventing me from saving a

I have tried using the conditions
[myString length]
myString == nil
myString == NULL

Additionally where is the best place in the iOS documentation to read up on this?

Answer Source

<null> is how the NSNull singleton logs. So:

if (tel == (id)[NSNull null]) {
    // tel is null

(The singleton exists because you can't add nil to collection classes.)

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