Re: Unable to access a variable declared inside an if statement (Error: is shadowing variable)
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);
}
}
}
Re: Unable to access a variable declared inside an if statement (Error: is shadowing variable)
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
Unable to access a variable declared inside an if statement (Error: is shadowing variable)
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);
}
}
}
