BlockExample.m

int (^minusOne)(int);
minusOne = ^(int myNumber) {
    return myNumber - 1;
};

NSLog(@"%d", minusOne(3)); // Will print: 2

BlocksWithNSPredicate.m

NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init];
[dateFormatter setDateFormat:@"dd/mm/yyyy"];
	
NSDate *referenceDate = [dateFormatter dateFromString:@"16/08/2010"];
	
NSArray *otherDates = [NSArray arrayWithObjects:@"12/08/2010", @"25/10/1990", @"30/08/2010", @"25/12/2010", nil];
	
NSPredicate *findFutureDates = [NSPredicate predicateWithBlock: ^BOOL(id obj, NSDictionary *bind){
	return [referenceDate earlierDate: [dateFormatter dateFromString: (NSString *)obj]] == referenceDate;
}];
	
NSArray *futureDates = [otherDates filteredArrayUsingPredicate: findFutureDates];
	
[dateFormatter release];
	
NSLog(@"Block Predicate Arrays ======");
NSLog(@"Dates: %@", otherDates);
NSLog(@"Future Dates: %@", futureDates);

NOTES

These files are apart of a tutorial on AlexEckermann.com

SimpleNSPredicate.m

NSArray *fruits = [NSArray arrayWithObjects:@"Apple", @"Crabapple", @"Watermelon", @"Lemon", @"Raspberry", @"Rockmelon", @"Orange", @"Lime", @"Grape", @"Kiwifruit", @"Bitter Orange", @"Manderin", nil];
	
NSPredicate *findMelons = [NSPredicate predicateWithFormat:@"SELF contains[cd] 'melon'"];
NSArray *melons = [fruits filteredArrayUsingPredicate:findMelons];
	
NSPredicate *findApple = [NSPredicate predicateWithFormat:@"SELF beginswith 'Apple'"];
NSArray *apples = [fruits filteredArrayUsingPredicate:findApple];
	
NSPredicate *findRNotMelons = [NSPredicate predicateWithFormat:@"SELF beginswith 'R' AND NOT SELF contains[cd] 'melon'"];
NSArray *rNotMelons = [fruits filteredArrayUsingPredicate:findRNotMelons];

NSLog(@"Fruits: %@", fruits);
NSLog(@"Melons: %@", melons);
NSLog(@"Apples: %@", apples);
NSLog(@"RNotMelons: %@", rNotMelons);