Foundation - NSDictionary字典

字典的创建方法：

用简写形式定义一个字典

NSDictionary *dict = @{@"zbz":@"zhangbozhi",@"xzmly":@"hello"};
获取key对应的值：dict[@"zbz"]

+ (id)dictionaryWithObjectsAndKeys:(id)firstObject, ...;
+ (id)dictionaryWithDictionary:(NSDictionary *)dict;
- (id)initWithObjectsAndKeys:(id)firstObject, ...;
- (id)initWithDictionary:(NSDictionary *)otherDictionary;

字典的常用方法：

- (NSUInteger)count;
- (id)objectForKey:(id)aKey;
- (NSArray *)allKeysForObject:(id)anObject;//找到所有的值相同的键
- (NSArray *)allKeys;
- (NSArray *)allValues;

字典的元素的添加：

- (void)addEntriesFromDictionary:(NSDictionary *)otherDictionary;
- (void)setObject:(id)anObject forKey:(id <NSCopying>)aKey;

删除字典的元素：

- (void)removeAllObjects;
- (void)removeObjectsForKeys:(NSArray *)keyArray;
- (void)removeObjectForKey:(id)aKey;

重置可变字典

- (void)setDictionary:(NSDictionary *)otherDictionary;