Thanks, going through the article now. Already making sense. On Friday, 7 May 2021 at 19:19:19 UTC+1 axel.wa...@googlemail.com wrote:
> Number literals are untyped constants > <https://golang.org/ref/spec#Constants> in Go. They are represented as > arbitrary precision integers. > When you use an untyped constant in an expression (for example as part of > a return statement), it gets assigned a type - either the type that the > expression must have (for example based on the return statement, other > operands it's used with or if it's part of an argument), or its default > type (int, for integer constants). > In your case, the compiler knows that the return type is a `uint64`, you > use the literal in a return statement, so that's the type it assigns. > > There is a pretty extensive explanation of Go constants in this blog post > <https://blog.golang.org/constants#:~:text=In%20Go%2C%20const%20is%20a,%22%2B%22pher%22)%20.>. > > I recommend reading that, it's more clear than my explanation :) > > On Fri, May 7, 2021 at 8:10 PM iammadab <iamm...@gmail.com> wrote: > >> I solved a problem on exercism that involved bit shifting. >> >> There is a chess board with 64 squares, a grain of wheat is placed on the >> first square, for the second square you double the number of grains from >> the first (1 +1) = 2. For the third you double the previous (2 + 2) = 4. >> Continue this until the board is full. >> >> The total function below is to add up all the grains on all the squares >> to know how many grains are on the board. >> >> I defined grains as a uint64, shifted it and then returned the answer. >> >> func Total() uint64 { >> var grains uint64 = 1 >> return (grains << 64) - 1 >> } >> >> The mentor told me that is not needed. Modified the solution to look like >> this below >> func Total() uint64 { >> return (1 << 64) - 1 >> } >> And it still worked!! >> Which is something I was definitely not expecting. How does the compiler >> know the right amount of memory to allocate to the literal 1. >> >> Thanks >> >> -- >> 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...@googlegroups.com. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/golang-nuts/ceaa1baa-ca80-46e2-b6f5-2112adef17e9n%40googlegroups.com >> >> <https://groups.google.com/d/msgid/golang-nuts/ceaa1baa-ca80-46e2-b6f5-2112adef17e9n%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> > -- 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/9fe37c72-dee1-45bd-a3a5-1592ebb50962n%40googlegroups.com.
