给 Golang 结构体字段赋值

PointMove()xdxPrint

main()x = 3dx = 2Move()Print()xMove()Print()Final x=5

main()x = 3dx = 2Move()Print()xMove()Print()Final x=5

2014/07/28 15:49:44 New X=5
2014/07/28 15:49:44 Final X=3

我的代码有什么问题?

type Point struct {
  x, dx int
}

func (s Point) Move() {
  s.x += s.dx
  log.Printf("New X=%d", s.x)
}

func (s Point) Print() {
  log.Printf("Final X=%d", s.x)
}

func main() {
  st := Point{ 3, 2 };
  st.Move()
  st.Print()
}

推荐答案

此处需要使用指针，否则每次都只更改原始对象的副本.一切都是在 go 中按值传递.

You need to use a pointer here or you are only changing a copy of the original object every time. Everything is passed by value in go.

type Point struct {
  x, dx int
}

func (s *Point) Move() {
  s.x += s.dx
  log.Printf("New X=%d", s.x)
}

func (s *Point) Print() {
  log.Printf("Final X=%d", s.x)
}

func main() {
  st := Point{ 3, 2 };
  st.Move()
  st.Print()
}

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