自定义类型和原始类型之间的区别
问题描述：
I have a quick doubt about Go types.
type mystr string
var s1 mystr = "abc"
var s2 string = "abc"
Here s1 always takes string type which is similar to s2. My question is, why defining such types are allowed (which are of primitive types) in Go. When I can't even compare s1 to s2
if s1 == s2 // compilation error
What can be the use case to such scenario?
我对Go类型存有疑问。 p>
type mystr string
var s1 mystr =“ abc”
var s2 string =“ abc”
code> pre>
此处s1始终采用类似于s2的字符串类型。 我的问题是，为什么在Go中允许定义这样的 types em>（属于原始类型）。 当我什至无法比较s1和s2 p>
如果s1 == s2 //编译错误
code> pre>
这种情况下的用例是什么？ p>
div>
答
It is similar to extension methods in other programming languages. You can add your own behavior to your type (and cannot in standard type):
type MyStr string
func (s MyStr) Length() int {
return len(string(s))
}
func main() {
s := MyStr("hello")
fmt.Println(s.Length())
}