Switch on NSString in Objective-C

Switcher.m

//NOTE: split into 2 files

//Based on/inspired by this stackoverflow.com post: https://stackoverflow.com/a/10177956/1256015 by Graham Perks.

//------ Switcher.h
/**
 Example usage:
 @code
 NSString * someString = @"Hearts";
 
 [Switcher switchOnString:someString
                    using:@{
                               @"Spades":
                               ^{
                                   NSLog(@"Spades block");
                               },
                               @"Hearts":
                               ^{
                                   NSLog(@"Hearts block");
                               },
                               @"Clubs":
                               ^{
                                   NSLog(@"Clubs block");
                               },
                               @"Diamonds":
                               ^{
                                   NSLog(@"Diamonds block");
                               } 
                           } withDefault:
                               ^{
                                   NSLog(@"Default block");
                               }
];
 
 @endcode
*/
typedef void (^CaseBlock)();

@interface Switcher : NSObject
    
+ (void)switchOnString:(NSString *)tString
                 using:(NSDictionary<NSString *, CaseBlock> *)tCases
           withDefault:(CaseBlock)tDefaultBlock;
@end
    
//------ Switcher.m  
@implementation Switcher
    
+ (void)switchOnString:(NSString *)tString
                 using:(NSDictionary<NSString *, CaseBlock> *)tCases
           withDefault:(CaseBlock)tDefaultBlock {
    CaseBlock blockToExecute = tCases[tString];
    if (blockToExecute) {
        blockToExecute();
    } else {
        tDefaultBlock();
    }
}
    
@end
  

While Objective-C doesn't have a switch statement for NSString, this snippet allows you to use a dictionary where the NSString key looks up a code block to execute. Even lays out much like a switch statement. See the example code in the comment block.