iOS App Solutions

  @property offers a way to define the information that a class is intended to encapsulate. If you declare an object/variable using @property , then that object/variable will be accessible to other classes importing its class.   If you declare an object using @property in the header file, then you have to synthesize it using @synthesize in the implementation file.  Example: .h class @interface ExampleClass : NSObject @property (nonatomic, retain) NSString *name; @end .m class @implementation ExampleClass @synthesize name; @end Now the compiler will synthesize accessor methods for name . ExampleClass *newObject=[[ExampleClass alloc]init]; NSString *name1=[newObject name]; // get 'name' [obj setName:@“Tiger”]; List of attributes of @property : atomic. nonatomic. retain. copy. readonly. readwrite. assign. strong.   atomic : It is the default behaviour. If an object is declared as atomic then it becomes ...

In this post, i'll walk you through how to filter an NSArray using NSPredicates.  The first thing you'll need to decide is if you're filtering a number or a string. For strings, you can use any of the following filters: (NOTE: must be all caps) BEGINSWITH ENDSWITH LIKE MATCHES CONTAINS For numbers, you can use: != > >= < <= == Now that you know what kind of data you're going to filter on, we can build our predicate. Lets first assume we're filtering an array of strings: NSArray* data = @[@"Grapes", @"Apples", @"Oranges]; Using this array, lets filter on the letter "a" This means we'll want to use CONTAINS. So if we want to build a hard-coded string it would look something like: NSString* filter = @"%K CONTAINS %@"; We'll then take our filter string and create a predicate with it:  NSPredicate* predicate = [NSPredicate predicateWithFormat:filter, @...