## Python Type Hints
Python 3.9 introduces a new feature called "Type Alias" which allows developers to assign a name to an existing type. This feature comes in handy when working with complex type a
目录1、定义2、映射类型编译成class之后3、Kotlin中对typealias的应用4、注意1、定义typealias关键字的作用就是将一个类映射到另一个类上面，或者可以说是给一个类起个别名。从下面的代码我们可以看出，我String 这个类映射到了A这个类上面，然后分别用A和String创建两个对象，比较输出的结果是相等的。public typealias A = String
public
Swift allows functions to be used like any value when used in the language. This in the vernacular says that functions are “first-class citizens”. If you want a full example of this, scroll down to th
