I want to have a percentage sign in my string after a digit. Something like this: 75%. How can I have this done? I tried: [NSString stringWithFormat:@”%d\%”, someDigit]; But it didn’t work for me. 7 Answers 7 The code for percent sign in NSString format is %%. This is also true for NSLog() and printf() … Read more
What exactly does the __block keyword in Objective-C mean? I know it allows you to modify variables within blocks, but I’d like to know… What exactly does it tell the compiler? Does it do anything else? If that’s all it does then why is it needed in the first place? Is it in the docs … Read more
I’m originally a Java programmer who now works with Objective-C. I’d like to create an abstract class, but that doesn’t appear to be possible in Objective-C. Is this possible? If not, how close to an abstract class can I get in Objective-C? 2Best Answer 21 Typically, Objective-C class are abstract by convention only—if the author … Read more
What are the differences between implementing a @property with @dynamic or @synthesize? 8 s 8 @synthesize will generate getter and setter methods for your property. @dynamic just tells the compiler that the getter and setter methods are implemented not by the class itself but somewhere else (like the superclass or will be provided at runtime). … Read more
I need to test whether the object is of type NSString or UIImageView. How can I accomplish this? Is there some type of “isoftype” method? 7 s 7 If your object is myObject, and you want to test to see if it is an NSString, the code would be: [myObject isKindOfClass:[NSString class]] Likewise, if you … Read more
I’ve gone through the iBook from Apple, and couldn’t find any definition of it: Can someone explain the structure of dispatch_after? dispatch_after(<#when: dispatch_time_t#>, <#queue: dispatch_queue_t?#>, <#block: dispatch_block_t?#>) 26 s 26 A clearer idea of the structure: dispatch_after(when: dispatch_time_t, queue: dispatch_queue_t, block: dispatch_block_t?) dispatch_time_t is a UInt64. The dispatch_queue_t is actually type aliased to an NSObject, … Read more
How can I convert a NSString containing a number of any primitive data type (e.g. int, float, char, unsigned int, etc.)? The problem is, I don’t know which number type the string will contain at runtime. I have an idea how to do it, but I’m not sure if this works with any type, also … Read more
My app that worked fine on iOS 7 doesn’t work with the iOS 8 SDK. CLLocationManager doesn’t return a location, and I don’t see my app under Settings -> Location Services either. I did a Google search on the issue, but nothing came up. What could be wrong? 26 s 26 I ended up solving my own … Read more
It is to my understanding that one should use a forward-class declaration in the event ClassA needs to include a ClassB header, and ClassB needs to include a ClassA header to avoid any circular inclusions. I also understand that an #import is a simple ifndef so that an include only happens once. My inquiry is … Read more
I’m a Java head mainly, and I want a way to generate a pseudo-random number between 0 and 74. In Java I would use the method: Random.nextInt(74) I’m not interested in a discussion about seeds or true randomness, just how you accomplish the same task in Objective-C. I’ve scoured Google, and there just seems to … Read more