可以扩展go struct构造函数吗？

Question

given

type Rectangle struct {
    h, w int
}

func (rec *Rectangle) area() int {
    return rec.w * rec.h
}

Can you define a Square struct using Rectangle, so I can make use of area method? It is absolutely fine if it is not possible. I won't judge the language or cry or get upset. I am just learning the golang.

Answer 1

Go isn't classically object-oriented, so it doesn't have inheritence. It also doesn't have constructors. What it does have is embedding. Thus this is possible:

type Rectangle struct {
    h, w int
}

func (rec *Rectangle) area() int {
    return rec.w * rec.h
}

type Square struct {
    Rectangle
}

The main limitation here is that there's no way for the area() method to access fields that only exist in Square.