Example
NSMutableArray *array =
[NSMutableArray arrayWithObjects:@"Ken", @"Tim", @"Chris", @"Steve",@"Charlie",@"Melissa", nil];
NSPredicate *bPredicate =
[NSPredicate predicateWithFormat:@"SELF beginswith[c] 'c'"];
NSArray *beginWithB =
[array filteredArrayUsingPredicate:bPredicate];
// beginWith "C" contains { @"Chris", @"Charlie" }.
NSPredicate *sPredicate =
[NSPredicate predicateWithFormat:@"SELF contains[c] 'a'"];
[array filterUsingPredicate:sPredicate];
// array now contains { @"Charlie", @"Melissa" }
