Remove particular objects from an array based on objects from another array - iphone

Question

Setup: Have a UITableView which shows US golf courses with name, street, state etc.
UITableView's data source is a NSMutableArray of objects from my class GolfCourse called allGolfCourses.
Now I like to remove all west coast golf courses from allGolfCourses and create a new array called eastCoastGolfCourses. I have another NSArray with string objects of all west coast states (Abbreviations) called westCoastStates but having a hard time connecting these two.
How do I iterate through allGolfCourses and remove all objects which have a state Abbreviations found in westCoastStates array?
westCoastStates Array:
self.westCoastStates = [NSMutableArray arrayWithObjects:
#"CH",
#"OR",
#"WA",
nil];
GolfCourse.h
#interface GolfCourse : NSObject
#property (nonatomic, strong) NSString *longitude;
#property (nonatomic, strong) NSString *latitude;
#property (nonatomic, strong) NSString *clubName;
#property (nonatomic, strong) NSString *state;
#property (nonatomic, strong) NSString *courseInfo;
#property (nonatomic, strong) NSString *street;
#property (nonatomic, strong) NSString *city;
#property (nonatomic, strong) NSString *clubID;
#property (nonatomic, strong) NSString *phone;
#end
Note: NSString *state; contains the state abbreviation for example: FL
I know how to do this with a single argument but don't know how to check against all strings from westCoastStates array. Hope you can help.

Answer 1

How about?
NSSet* westCoastStatesSet = [NSSet setWithArray:self.westCoastStates];
NSIndexSet* eastCoastGolfCoursesIndexSet = [allGolfCourses indexesOfObjectsPassingTest:^BOOL(id obj, NSUInteger idx, BOOL *stop) {
GolfCourse* course = (GolfCourse*)obj;
if ([westCoastStatesSet containsObject:course.state]) {
return NO;
}
return YES;
}];
NSArray* eastCoastGolfCourses = [allGolfCourses objectsAtIndexes:eastCoastGolfCoursesIndexSet];
Update: I believe this could be condensed with the use of predicates
NSPredicate *inPredicate = [NSPredicate predicateWithFormat: #"!(state IN %#)", self.westCoastStates];
NSArray* eastCoastGolfCourses = [allGolfCourses filteredArrayUsingPredicate:inPredicate];

Answer 2

Pseudo-code:
for (int i = 0; i < allGolfCourses.length;) {
Course* course = [allGolfCourses objectAtIndex:i];
if (<is course in one of the "bad" states?>) {
[allGolfCourse removeObjectAtIndex:i];
}
else {
i++;
}
}

Answer 3

You can quickly iterate on an array like this:
[self.allGolfCourses enumerateObjectsUsingBlock:^(id obj, NSUInteger idx, BOOL *stop) {
GolfCourse *currentGolfCourse = (GolfCourse *)obj;
if(![self.westCoastStates containsObject:currentGolfCourse.state]){
[self.eastCoastStates addObject:currentGolfCourse];
}
}];