IOS/Objective-C: Build NSDictionary from NSManagedObject - ios

Question

I am trying to build an NSDictionary from an NSManagedObject. I was under the impression that you could do this with: NSMutableDictionary *myDict;
[myDict setObject:self.title forKey:#"title"];
}
Because a dictionary cannot hold nil values, I am testing for nil first. However, when I verify using a break that properties have values, when I build the dictionary it is nil. It shows as nil using a breakpoint and logs to console as NULL. Would appreciate someone confirming that the following is a valid way to create a dictionary and, if so, why the dictionary would be nil?
NSString *title = #"Test";
NSNumber *complete = #1;
NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
dateFormatter.dateFormat = #"yyyy-MM-dd HH:mm:ss";
NSString *lasttouchedstr =[dateFormatter stringFromDate:[NSDate date]];
NSMutableDictionary *myDict;
if (self.title.length>=1) {
[myDict setObject:self.title forKey:#"title"];
}
if (![self.complete isKindOfClass:[NSNull class]]) {
[myDict setObject:self.complete forKey:#"complete"];
}
if (![self.lasttouched isKindOfClass:[NSNull class]]) {
[myDict setObject:lasttouchedstr forKey:#"lasttouchedstr"];
}
NSLog(#"myDict is:%#",myDict)//Logs as NULL
return myDict;
Thanks in advance for any suggestions.

Answer 1

NSMutableDictionary *myDict; declares the value but does not initialize it. You need
NSMutableDictionary *myDict = [[NSMutableDictionary alloc] init];
Secondly, managed objects will not be returning a value of NSNull for any of their attributes. You need to check for != nil instead. See here for a nice explanation of the differences between nulls and nils.