Variable not initialized?

[Skrim 11]

I get this warning, what does it mean?

[dcc32 Warning] HovedUnit.pas(13295): W1036 Variable 'j' might not have been initialized

 

J is an integer.

 

Do I have to do, J:=0;

[Remy Lebeau 1398]

Depends on the context. The compiler thinks you are using J's value before you have actually assigned any value to J. Sometimes the compile makes a mistake on this, sometimes not, so it may or may not be a false positive. How are you actually using J exactly? Can you show that code? 

Edited March 17 by Remy Lebeau

[Lars Fosdal 1792]

Frequent scenario

function Test: integer;
var
  i: integer;
begin
  try
    i := 1;
    // do something
  finally;
    Result := i;
  end;
end;

i needs to be initialized before the try block.

[Skrim 11]

On 3/17/2024 at 5:31 PM, Remy Lebeau said:

Depends on the context. The compiler thinks you are using J's value before you have actually assigned any value to J. Sometimes the compile makes a mistake on this, sometimes not, so it may or may not be a false positive. How are you actually using J exactly? Can you show that code? 

Here is my code, also could it be done easier/more elegant 

 

//  String 000001203 to 1203

// Numbers of zeros to the left could be 1..n

function RemoveZeroLeft(var s : String) : string;
var
  i, j : integer;
begin

  for i:=1 to length(s)do
  begin
    if s<>#48 then
    begin
      j:=i;
      break;
    end;
  end;

  result:=copy(s,j,length(s));

end;

[Stano 143]

If the condition "if s<>#48 then" is never satisfied, then j is not initialized.
immediately after begin, initialize the variable. I use inline var for this.

[Remy Lebeau 1398]

I would opt to simply eliminate J altogether:

function IndexOfFirstNotOf(const s: string; Ch: Char): Integer;
begin
  for Result := 1 to Length(s) do begin
    if s[Result] <> Ch then Exit;
  end;
  Result := 0;
end;

function RemoveZeroLeft(const s : String) : string;
var
  i : integer;
begin
  i = IndexOfFirstNotOf(s, '0');
  if i > 1 then
    Result := Copy(s, 1, MaxInt)
  else if i = 1 then
    Result := s
  else
    Result := ''; // or '0' if needed
end;

 

Edited March 19 by Remy Lebeau

[Stefan Glienke 2006]

https://docwiki.embarcadero.com/Libraries/Athens/en/System.SysUtils.TStringHelper.TrimLeft