Good, straight forward article on NSPredicate use…
How To Do Amazingly Simple Searches With NSArray & NSPredicate.
Here are the steps required to search arrays with NSPredicate:
Find or create an NSArray full of objects with interesting properties Create an NSPredicate object with the search query that you want to use You can use this NSPredicate object to either filter the array or create a new array with a subset of data
[code]
NSPredicate *predicate = [NSPredicate predicateWithFormat:@"dept == Dev"];
NSArray *devEmps = [emps filteredArrayUsingPredicate:predicate];
[/code]