go - 使用字符串定义的类型值作为字符串

Question

我有一个定义的命名类型

type User string

现在我想像这样使用一个User值作为一个实际的字符串

func SayHello(u User) string {
    return "Hello " + user + "!"
}

但是我收到一个错误:

cannot use "Hello " + user + "!" (type User) as type string in return argument

如何使用命名类型作为其基础类型？

Answer 1

Go does not have typedefs .

Two types are either identical or different.

A defined type is always different from any other type.

User 是定义的类型，因此不同于字符串类型。

由于 User 的底层类型是字符串，您可以简单地 convert from one type to the other :

"Hello " + string(user) + "!"