Objective C Pros:
can support C++ library
weak typed language, differences, 可以不同类型一起运算
sending nil to object will not crash the app
has macro
Objective C Cons:
no namespace
Swift provides more powerful collection types, array, set, dictionary.
Swift also provides some advanced data type : Tuples.
swift introduce 可选类型(Optionals),用于处理变量值不存在的情况。to represent the instance is not existed or invalid
- 可选项的意思有两种:一是变量是存在的,例如等于X,二是变量值根本不存在。
- Optionals similiar with Objective-C中指向nil的指针,但是适用于所有的数据类型,而非仅仅局限于类
- Optionals 相比于Objective-C中nil指针更加安全和简明,并且也是Swift诸多最强大功能的核心。
- more safe and elegant with Swift syntax sugar, only add a "question mark" to use