Learning Cocoa with Objective-C
by Parker · 11 things on Twos
- Use NSNumber to store numbers in NSArrays and NSDictionaries: @123
- int myValue = [theNumber intValue];
- NSNumber *number = @(a + 1);
- Blocks allow you to store chunks of code in variables and call them later
- You must copy a block to be able to access it after a method
- In order to modify a variable, that is declared outside of the block, inside the block you must mark the variable with the __block keyword
- A frame rectangle is defined relative to its superview
- Bounds rectangle is the view's position and size relative to its own coordinate space
- for (NSString* key in dictionary) {
NSObject* theValue = [dictionary objectForKey:key];
[aProduct setValue:theValue forKey:key];
}
- If you try to set a value for a key that does not exist in your class, the key-value coding system will throw an exception because the runtime won’t know where to store the value
- Notifications come with a special aps dictionary which contains information about how the push notification should be presented