字符串、數組、字典

字符串：

不可變初始化 NSString 

NSString *string =  @“”；//直接賦值

NSString *string = [NSString string];初始化

NSString *string =[[NSString alloc]init];初始化

NSString *string = [NSString stringWithFormat:@“01.f”,score];//直接格式化字符串

可變字符串 NSMutableString

初始化：NSMutableString *string = [NSMutableString string];

              NSMutableString *string = [[NSMutableString alloc]init];

NSMutableString *string = [NSMutableString stringWithString@“"];

NSMutableString *string = [NSMutableString@“”];

數組：NSArray 

不可變

初始化

NSArray *array = @[@“”,@“”,@“”];//直接賦值

NSArray *array = [[NSArray alloc]init];//初始化

NSArray *array = [NSArray array];初始化

初始化並賦值：

NSArray *list = [NSArray arrayWithObject:@“”];//初始化只有一個元素的數組

NSArray *list = [NSArray arrayWithObjects:@“”@“”，nil];//初始化只有一個元素的數組

可變

NSMutableArray *list = [NSMutableArray arrayWithArray@[@“”,@“"]];

NSMutableArray *list = [NSMutableArray stringWithFormat];

字典 NSDictionary

不可變

NSDictionary *dic = @{@“key”:@“z”,@“key2”:@“z2”};//直接賦值

NSDictionary *dic = [[NSDictionary alloc]init];初始化

NSDictionary *dic = [NSDictionary dictionary];初始化

NSDictionary *dic= [NSDictionary dictionaryWithObject:@“z”,forKey:@“key" ];

NSDictionary *dic= [NSDictionary dictionaryWithObjectsAndKeys:@“z”,@“key”,nil ];