C switch on NSString?

有没有更聪明的方法来重写？

if ([cardName isEqualToString:@"Six"]) {
    [self setValue:6];
} else if ([cardName isEqualToString:@"Seven"]) {
    [self setValue:7];
} else if ([cardName isEqualToString:@"Eight"]) {
    [self setValue:8];
} else if ([cardName isEqualToString:@"Nine"]) {
    [self setValue:9];
} 

---

Unfortunately they cannot. This is one of the best and most sought after utilizations of switch statements, so hopefully they hop on the (now) Java (and others) bandwagon!

If you are doing card names, perhaps assign each card object an integer value and switch on that. Or perhaps an enum, which is considered as a number and can therefore be switched upon.

eg

typedef enum{
  Ace, Two, Three, Four, Five ... Jack, Queen, King

} CardType;

Done this way, Ace would be be equal to case 0, Two as case 1, etc.

---

You could set up a dictionary of blocks, like this:

NSString *lookup = @"Hearts"; // The value you want to switch on

typedef void (^CaseBlock)();

// Squint and this looks like a proper switch!
NSDictionary *d = @{
    @"Diamonds": 
    ^{ 
        NSLog(@"Riches!"); 
    },
    @"Hearts":
    ^{ 
        self.hearts++;
        NSLog(@"Hearts!"); 
    },
    @"Clubs":
    ^{ 
        NSLog(@"Late night coding > late night dancing"); 
    },
    @"Spades":
    ^{ 
        NSLog(@"I'm digging it"); 
    }
};

((CaseBlock)d[lookup])(); // invoke the correct block of code

To have a 'default' section, replace the last line with:

CaseBlock c = d[lookup];
if (c) c(); else { NSLog(@"Joker"); }

Hopefully Apple will teach 'switch' a few new tricks.

---

对我来说，一个简单的方法：

NSString *theString = @"item3";   // The one we want to switch on
NSArray *items = @[@"item1", @"item2", @"item3"];
int item = [items indexOfObject:theString];
switch (item) {
    case 0:
       // Item 1
       break;
    case 1:
       // Item 2
       break;
    case 2:
       // Item 3
       break;
    default:
       break;
}

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