Four dictionaries of Data Types in objective-C (nsdictionary)

// 1. 字典初始化、赋值方式1    NSMutableDictionary *m_dictionary = [[NSMutableDictionary alloc] initWithCapacity:0];    [m_dictionary setObject:@1 forKey:@"语文"];    [m_dictionary setObject:@2 forKey:@"数学"];    [m_dictionary setObject:@3 forKey:@"英语"];    // 字典初始化、赋值方式2    NSDictionary *dict1 = @{@"语文": @1, @"数学": @2, @"英语": @3};    m_dictionary = [NSMutableDictionary dictionaryWithDictionary:dict1];        // 字典初始化、赋值方式3    m_dictionary = [NSMutableDictionary dictionaryWithObjectsAndKeys: @1, @"语文", @2, @"数学", @3, @"英语", nil];    // 字典初始化、赋值方式4    m_dictionary = [NSMutableDictionary dictionaryWithObjects:@[@1, @2, @3] forKeys:@[@"语文", @"数学", @"英语"]];    // 赋值方式5    NSDictionary *dict2 = @{ @"物理": @4};    [m_dictionary addEntriesFromDictionary:dict2];        // 2. 排序 方式1    NSArray *sortedKeysArray =    [m_dictionary keysSortedByValueUsingSelector:@selector(compare:)];    // sortedKeysArray (语文, 数学, 英语, 物理)    // 方式2    NSArray *blockSortedKeys = [m_dictionary keysSortedByValueUsingComparator: ^(id obj1, id obj2) {        return [obj1 compare:obj2];    }];    // blockSortedKeys (语文, 数学, 英语, 物理)

Four dictionaries of Data Types in objective-C (nsdictionary)