How to check the NULL value in NSString in iOS?

Question

I have an NSString and I want to check if it has a NULL value. If it does, then the if condition should execute. Else it should execut

Answer 1

Use the following code:

-(void)viewDidLoad {
  [super viewDidLoad];
  //Example - 1
    NSString *myString;
    if([[self checkForNull:myString] isEqualToString:@""]){

        NSLog(@"myString is Null or Nil");

   }
   else{

     NSLog(@"myString contains %@",myString);

   }

 //Example - 2
   NSString *sampleString = @"iOS Programming";
    if([[self checkForNull:sampleString] isEqualToString:@""]){

        NSLog(@"sampleString is Null or Nil");

   }
   else{

     NSLog(@"sampleString contains %@",sampleString);

   }


}

-(id)checkForNull:(id)value{
    if ([value isEqual:[NSNull null]]) {

            return @"";
   }

    else if (value == nil)

            return @"";
    return value;

}

In Example -1, myString contains nothing. So the output is:

         myString is Null or Nil

In Example -2, sampleString contains some value. So the output is:

    sampleString contains iOS Programming