Objective-Cのいろいろな反復処理

Test.m

- (void)test
{
    NSArray *anArray = @[@"a", @"b", @"c"];
    
    NSDictionary *aDictionary = @{@"key1": @"val1",
                                  @"key2": @"val2",
                                  @"key3": @"val3"};
    
    // for loop
    for (int i = 0; i < anArray.count; i++)
    {
        id object = anArray[i];
        NSLog(@"object = %@", object);
    }
    
    NSArray *keys = [aDictionary allKeys];
    for (int i = 0; i < keys.count; i++)
    {
        id key = keys[i];
        id value = aDictionary[key];
        NSLog(@"key = %@, value = %@", key, value);
    }
    
    // 高速反復処理
    for (id object in anArray)
    {
        NSLog(@"object = %@", object);
    }

    for (id object in [anArray reverseObjectEnumerator])
    {
        NSLog(@"object = %@", object);
    }

    for (id key in aDictionary)
    {
        id value = aDictionary[key];
        NSLog(@"key = %@, value = %@", key, value);
    }
    
    // blocks
    [anArray enumerateObjectsUsingBlock:
     ^(NSString *object, NSUInteger idx, BOOL *stop) {
         NSLog(@"object = %@, idx = %lu", object, (unsigned long)idx);
     }];
    [anArray enumerateObjectsWithOptions:NSEnumerationReverse
                              usingBlock:
     ^(NSString *object, NSUInteger idx, BOOL *stop) {
         NSLog(@"object = %@, idx = %lu", object, (unsigned long)idx);
     }];
    
    [aDictionary enumerateKeysAndObjectsUsingBlock:
     ^(id key, id object, BOOL *stop) {
         NSLog(@"key = %@, object = %@", key, object);
    }];
    [aDictionary enumerateKeysAndObjectsWithOptions:NSEnumerationReverse
                                         usingBlock:
     ^(id key, id object, BOOL *stop) {
         NSLog(@"key = %@, object = %@", key, object);
     }];
}