I'm lacking knowledge on how to achieve what I want and getting an error.
What is the correct way to do what I tried to achieve in this code?
Everything was intuitive until I started to add notice variable to the writeln. Rdmd says  variable `notice` is shadowing variable.

rdmd output:
> C:\Users\vaida\Desktop>rdmd searchDirectory.d
> searchDirectory.d(21): Error: variable `notice` is shadowing variable `searchDirectory.main.notice`
> Failed: ["C:\\D\\dmd2\\windows\\bin\\dmd.exe", "-v", "-o-", "searchDirectory.d", "-I."]

searchDirectory.d
> import std.stdio : writeln;
> import std.file;
> void main(){
> 
> 	auto drivesLetters = [
> 		"A:", "I:", "Q:", "Y:",
> 		"B:", "J:", "R:", "Z:",
> 		"C:", "K:", "S:", 		"D:", "L:", "T:",
> 		"E:", "M:", "U:",
> 		"F:", "N:", "V:",
> 		"G:", "O:", "W:",
> 		"H:", "P:", "X:",
> 	];
> 	
> 	foreach (string driveLetter; drivesLetters) {
> 		string notice;
> 		if (driveLetter.exists){
> 			auto directory = "/Backup";
> 			if ((driveLetter ~ directory).exists){
> 				auto notice = "Backup directory exists.";
> 				
> 			}
> 			writeln(driveLetter, notice);
> 		}
> 		
> 	}
> 
> 	
> }

On Wednesday, 27 May 2020 at 11:03:51 UTC, BoQsc wrote:
> I'm lacking knowledge on how to achieve what I want and getting an error.
> What is the correct way to do what I tried to achieve in this code?
> Everything was intuitive until I started to add notice variable to the writeln. Rdmd says  variable `notice` is shadowing variable.
>
>> 		if (driveLetter.exists){
>> 			auto directory = "/Backup";
>> 			if ((driveLetter ~ directory).exists){
>> 				auto notice = "Backup directory exists.";
>> 				
>> 			}
>> 			writeln(driveLetter, notice);
>> 		}

Variables only live in a specified scope, starting from where they are declared, and ending when they reach the '}' indicating the end of said scope.

In you case, 'notice' only lives inside the if ((driveLetter ~ directory).exists) scope, and doesn't exist outside. In order to fix this, you will need to declare it outside:

    if (driveLetter.exists) {
        auto directory = "/Backup";
        auto notice = "Backup directory does not exist.";
        if ((driveLetter ~ directory).exists) {
            notice = "Backup directory exists.";
        }
        writeln(driveLetter, notice);
    }

This also makes it clearer what value 'notice' will have when the backup directory doesn't exist - in your case you haven't assigned it any value in that case.

--
  Simen

On Wednesday, 27 May 2020 at 11:13:09 UTC, Simen Kjærås wrote:
> On Wednesday, 27 May 2020 at 11:03:51 UTC, BoQsc wrote:
>> I'm lacking knowledge on how to achieve what I want and getting an error.
>> What is the correct way to do what I tried to achieve in this code?
>> Everything was intuitive until I started to add notice variable to the writeln. Rdmd says  variable `notice` is shadowing variable.
>>
>>> 		if (driveLetter.exists){
>>> 			auto directory = "/Backup";
>>> 			if ((driveLetter ~ directory).exists){
>>> 				auto notice = "Backup directory exists.";
>>> 				
>>> 			}
>>> 			writeln(driveLetter, notice);
>>> 		}
>
> Variables only live in a specified scope, starting from where they are declared, and ending when they reach the '}' indicating the end of said scope.
>
> In you case, 'notice' only lives inside the if ((driveLetter ~ directory).exists) scope, and doesn't exist outside. In order to fix this, you will need to declare it outside:
>
>     if (driveLetter.exists) {
>         auto directory = "/Backup";
>         auto notice = "Backup directory does not exist.";
>         if ((driveLetter ~ directory).exists) {
>             notice = "Backup directory exists.";
>         }
>         writeln(driveLetter, notice);
>     }
>
> This also makes it clearer what value 'notice' will have when the backup directory doesn't exist - in your case you haven't assigned it any value in that case.
>
> --
>   Simen

That's correct. Thanks Simen.

> import std.stdio : writeln;
> import std.file;
> void main(){
> 
> 	auto drivesLetters = [
> 		"A:", "I:", "Q:", "Y:",
> 		"B:", "J:", "R:", "Z:",
> 		"C:", "K:", "S:", 		"D:", "L:", "T:",
> 		"E:", "M:", "U:",
> 		"F:", "N:", "V:",
> 		"G:", "O:", "W:",
> 		"H:", "P:", "X:",
> 	];
> 	
> 	foreach (string driveLetter; drivesLetters) {
> 		if (driveLetter.exists) {
> 				auto notice = "";
> 				if ((driveLetter ~ "/Boot").exists) {
> 					notice ~= "\\Boot directory exists";
> 					notice ~= " ";
> 				}
> 				if ((driveLetter ~ "/Windows").exists) {
> 					notice ~= "\\Windows folder exists";
> 					notice ~= " ";
> 				}
> 				writeln(driveLetter, notice);
> 			}
> 		
> 	}
> 
> 	
> }