On Wed, Jan 27, 2021 at 5:13 PM Barry Li <barrya...@gmail.com> wrote: > > Some doubts about type conversion in go. > In the following code, why can it be executed normally after passing the > variable? > The code is an error during the compilation phase. > > // The following two lines of code can be executed normally > x := uint64(256) > fmt.Println(byte(uint64(x))) // normal execution > > // The following code cannot be executed normally > fmt.Println(byte(uint64(256))) // constant 256 overflows byte > > Can anyone help me answer it?
In Go, arithmetic on constant values follows different rules than arithmetic on variable values. For example, as you've seen, an out-of-range conversion is a compilation error for constants but a run time error for variables. The same is true of division by zero. See https://golang.org/ref/spec#Constant_expressions. Ian -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/golang-nuts/CAOyqgcXCx4E%2B0O4a-ZM7Rc2x%3D-fJmK_UQknePE%2BgkSoDpoAuVA%40mail.gmail.com.
