Menu
ERROR: type CustomStruct is not an expression.
type CustomStruct struct { } func getTypeName(t interface{}) string { rt := reflect.TypeOf(t).Elem() return rt.Name() } getTypeName(CustomStruct) How can I pass struct type to function without type instance?
This will work
getTypeName((*CustomStruct)(nil)) But I wonder if there is more simple version..
223
Golang supports two different ways to pass arguments to the function i.e. Pass by Value or Call by Value and Pass By Reference or Call By Reference. By default, Golang uses the call by value way to pass the arguments to the function.
You can't. You can only pass a value, and CustomStruct is not a value but a type. Using a type identifier is a compile-time error.
In Golang, a function that can be called with a variable argument list is known as a variadic function. One can pass zero or more arguments in the variadic function. If the last parameter of a function definition is prefixed by ellipsis …, then the function can accept any number of arguments for that parameter.
func: It is a keyword in Go language, which is used to create a function. function_name: It is the name of the function. Parameter-list: It contains the name and the type of the function parameters. Return_type: It is optional and it contain the types of the values that function returns.
You can't. You can only pass a value, and CustomStruct is not a value but a type. Using a type identifier is a compile-time error.
Usually when a "type" is to be passed, you pass a reflect.Type value which describes the type. This is what you "create" inside your getTypeName(), but then the getTypeName() will have little left to do:
func getTypeName(t reflect.Type) string { return t.Name() } // Calling it: getTypeName(reflect.TypeOf(CustomStruct{})) (Also don't forget that this returns an empty string for anonymous types such as []int.)
Another way is to pass a "typed" nil pointer value as you did, but again, you can just as well use a typed nil value to create the reflect.Type too, without creating a value of the type in question, like this:
t := reflect.TypeOf((*CustomStruct)(nil)).Elem() fmt.Println(t.Name()) // Prints CustomStruct If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
