NSString+Comparisons

NSString+Comparisons.h

@interface NSString (Comparisons)

- (BOOL)containsString:(NSString *)substring;
- (BOOL)isSubstringOfString:(NSString *)string;
- (BOOL)isEqualToAnyOfStrings:(NSArray *)strings;
- (BOOL)isEqualToNoneOfStrings:(NSArray *)strings;

@end

NSString+Comparisons.m

#import "NSString+Comparisons.h"

@implementation NSString (Comparisons)

- (BOOL)containsString:(NSString *)substring {
    NSRange range = [self rangeOfString:substring];
    return (range.location != NSNotFound);
}

- (BOOL)isSubstringOfString:(NSString *)string {
    NSRange range = [string rangeOfString:self];
    return (range.location != NSNotFound);
}

- (BOOL)isEqualToAnyOfStrings:(NSArray *)strings {
    for (NSString *string in strings) {
        if ([self isEqual:string]) return YES;
    }
    return NO;
}

- (BOOL)isEqualToNoneOfStrings:(NSArray *)strings {
    for (NSString *string in strings) {
        if ([self isEqual:string]) return NO;
    }
    return YES;
}

@end