如何将变量与 NSArray 内的 NSDictionary 内的对象进行比较？

Question

我需要将 NSString 变量与存储在 NSMutableArray 内的 NSDictionary 中的对象进行比较

我的 NSMutableArray 包含 Manu NSDictionaries，每个 NSDictionaries 都有两个 NSString 对象

在我向数组添加更多整体之前，我想确保它不在其中，但那时我只知道其中一个对象名称

例如

NSDictionary 保存 @"foo" 键 @"bar" 和 @"Jongel" 键 @"fibbel"

现在我想构建一个新的 NSDictionary 并将其插入到数组中，但前提是 NSString @"foo" 不在数组中的字典中

我找不到任何有关如何在数组中寻址 NSDictionary 的文档，我可以找到有关如何使用 NSArray *myArray = dict[0] 在 nsdictionary 中查找数组然后循环遍历的文档，但这就是我需要的我需要走另一条路

如何做到这一点？

这是我正在尝试的方法，但我做不对

+ (void) splitOutCategories:(NSMutableArray *)reveProducts {
    if([NWTillHelper isDebug] == 1) {
        NSLog(@"%s entered with array count = %lu", __PRETTY_FUNCTION__, reveProducts.count);
    }

    NSMutableArray *reveCollections = [[NSMutableArray alloc] init];

    for (NSDictionary *dictProduct in reveProducts) {
        NSMutableDictionary *dictReveCollections = [[NSMutableDictionary alloc] init];
        NSArray *arrLocales = dictProduct[@"locales"];
        for (NSDictionary *dictLocale in arrLocales) {
            NSArray *arrCategories = dictLocale[@"categories"];
            NSArray *arrImages = dictLocale[@"images"];
            if(arrCategories.count < 1) {
                // Nothing to do
            } else if (arrCategories.count == 1) {
                if(![reveCollections containsObject:arrCategories[0]]) {
                    // Here we need to build the entire dict and insert into the array
                    NSString *fcTitle = arrCategories[0];
                    NSString *fcImageUrl = arrImages[0];
                    [dictReveCollections setObject:fcTitle forKey:@"fcTitle"];
                    [dictReveCollections setObject:fcImageUrl forKey:@"fcImageUrl"];
                    [reveCollections addObject:dictReveCollections];
                }
            } else if (arrCategories.count > 1) {
                if(![reveCollections containsObject:arrCategories[1]]) {
                    NSString *fcTitle = arrCategories[1];
                    NSString *fcImageUrl = nil;
                    if(arrImages.count < 1) {
                        fcImageUrl = @"https://xxxxyyyyy.png";
                    } else {
                        fcImageUrl = arrImages[0];
                    }
                    [dictReveCollections setObject:fcTitle forKey:@"fcTitle"];
                    [dictReveCollections setObject:fcImageUrl forKey:@"fcImageUrl"];
                    [reveCollections addObject:dictReveCollections];
                }
            }
        }
    }
    NSLog(@"reveCollectionsArray = \r\n%@", reveCollections);
    NSLog(@"reveCollectionsArrayCount = %lu", reveCollections.count);
}

Answer 1

Before I add more entires to the Array I want to make sure its not already in there

此处的解决方案取决于具体需要独特的内容。正如您所描述的，听起来只有 NSDictionary key/value 对的值需要是唯一的（"foo"、"Jongel"）。如果是这种情况，那么您可以通过使用 NSMutableSet 跟踪您已经接受的值来非常轻松解决这个问题。

这样的方法可行：

@interface CollectionExample ()
@property (strong, nonatomic) NSMutableArray *reveCollections;
@property (strong, nonatomic) NSMutableSet *storedValues;
@end

@implementation CollectionExample

- (instancetype)init {
    self = [super init];
    if (self) {
        _storedValues = [NSMutableSet set];
        _reveCollections = [NSMutableArray array];
    }
    return self;
}

- (BOOL)valueAlreadyExists:(NSString *)newValue {
    return [self.storedValues containsObject:newValue];
}

- (void)addNewKeyValuePair:(NSString *)key value:(NSString *)value {
    if ([self valueAlreadyExists:value]) {
        // handle this however you'd like
        return;
    }
    NSDictionary *dict = @{key: value};
    [self.reveCollections addObject:dict];
    [self.storedValues insertObject:value];
}

@end

但是，如果需要唯一的是 key/value 对，那么您必须遍历数组 and 遍历每个字典中的每个 key/value 对。这样的事情应该有效：

- (BOOL)valueAlreadyExists:(NSString *)newKey value:(NSString *)newValue {
    BOOL foundPair = NO;
    for (NSDictionary *dict in self.reveCollections) {
        [dict enumerateKeysAndObjectsUsingBlock:^(id  _Nonnull key, id  _Nonnull obj, BOOL * _Nonnull stop) {
            if ([newKey isEqualToString:key] && [newValue isEqualToString:obj]) {
                foundPair = YES;
                *stop = YES;
                return;
            }
        }];
    }
    return foundPair;
}

如何将变量与 NSArray 内的 NSDictionary 内的对象进行比较？

How to compare a variable to an object inside an NSDictionary that is inside an NSArray?

objective-c

nsmutablearray

nsdictionary