Golang 使用reflect 更改struct内容

type MyStruct struct {
N int
}
n := MyStruct{ 1 }

// get
immutable := reflect.ValueOf(n)
val := immutable.FieldByName("N").Int()
fmt.Printf("N=%d\n", val) // prints 1

// set
mutable := reflect.ValueOf(&n).Elem()
mutable.FieldByName("N").SetInt(7)
fmt.Printf("N=%d\n", n.N) // prints 7