CODEWITHSUNDEEP
delphidelphi-10.1-berlin
Relinkvent
Relinkvent

Reputation: 113

Delphi remove symbols from String

I have searched and tried a couple of loops which are supposed to remove symbols from a string, I need this because certain locations can have a "/" or other type of symbol and I need it removed since FTP will think it's a folder, and I need the string in a name.

The String 'place' varies from the persons current working location, for example there's a 'place' = "S/A StorageRoom", the '/' part of the String make's FTP think that it's a subfolder.

For now I'm using this, which I think is pretty large and could use 'shortening':

   place := StringReplace(place, ',', '', [rfReplaceAll]);
   place := StringReplace(place, '.', '', [rfReplaceAll]);
   place := StringReplace(place, '/', '', [rfReplaceAll]);
   place := StringReplace(place, '!', '', [rfReplaceAll]);
   place := StringReplace(place, '@', '', [rfReplaceAll]);
   place := StringReplace(place, '#', '', [rfReplaceAll]);
   place := StringReplace(place, '$', '', [rfReplaceAll]);
   place := StringReplace(place, '%', '', [rfReplaceAll]);
   place := StringReplace(place, '^', '', [rfReplaceAll]);
   place := StringReplace(place, '&', '', [rfReplaceAll]);
   place := StringReplace(place, '*', '', [rfReplaceAll]);
   place := StringReplace(place, '''', '', [rfReplaceAll]);
   place := StringReplace(place, '"', '', [rfReplaceAll]);
   place := StringReplace(place, ';', '', [rfReplaceAll]);
   place := StringReplace(place, '_', '', [rfReplaceAll]);
   place := StringReplace(place, '(', '', [rfReplaceAll]);
   place := StringReplace(place, ')', '', [rfReplaceAll]);
   place := StringReplace(place, ':', '', [rfReplaceAll]);
   place := StringReplace(place, '|', '', [rfReplaceAll]);
   place := StringReplace(place, '[', '', [rfReplaceAll]);
   place := StringReplace(place, ']', '', [rfReplaceAll]);
   place := StringReplace(place, '\', '', [rfReplaceAll]);

Edit: I'm currently using RAD Studio 10.1 Berlin

Upvotes: 3

Views: 13772

Answers (2)

LU RD
LU RD

Reputation: 34899

In a quest to avoid unnecessary heap allocations, here is a variant of @Ancaron's answer that only does one allocation and a final size reduction in order to produce the answer.

The trick is to preallocate the resulting string at the beginning, and then fill it up with accepted characters. At the end, adjust the resulting string length.

program TestStripChars;

{$APPTYPE CONSOLE}

uses
  SysUtils;

function StripChars (const Text : string; const InValidChars : SysUtils.TSysCharSet) : string;
var
  i,j : Integer;
begin
  SetLength(Result,Length(Text));  // Preallocate result maximum length
  j := 0;  // Resulting string length counter
  for i := 1 to Length(Text) do begin
    if not CharInSet(Text[i],InValidChars) then begin
      Inc(j);
      Result[j] := Text[i];
    end;
  end;
  SetLength(Result,j); // Set result actual length
end;

var
  place : String;
begin
  place := 'Hell$$o D.,e.$lphi';
  place := StripChars(place,[',','.','$']);
  WriteLn(place);
  ReadLn;
end.

From a comment it looks like the OP is using a compiler setting with zero based string handling.

Here is a function that handles both scenarios:

function StripChars ( const Text : string; const InValidChars : SysUtils.TSysCharSet) : string;
var
  i,j,zbsAdj : Integer;
begin
  SetLength(Result,Length(Text));  // Preallocate result maximum length
  j := 0; // Resulting string length counter
  zbsAdj := 1-Low(String); // Handles zero based string offset
  for i := Low(Text) to High(Text) do begin
    if not CharInSet(Text[i],InValidChars) then begin
      Inc(j);
      Result[j-zbsAdj] := Text[i];
    end;
  end;
  SetLength(Result,j); // Set result actual length
end;

Upvotes: 6

Ancaron
Ancaron

Reputation: 504

You cold just use a function like 

function StripChars ( const Text : string; InValidChars : TSetOfChar ) : string;
var
  S : string;
  i : integer;
begin
  Result := '';
  if Length(Text) > 0 then
  begin
    S := '';
    for i := 1 to length ( Text ) do
      if not CharInSet(Text[i],InValidChars) then  
        S := S + Text [ i ];
    Result := S;
  end;
end;

and then only call 

place := StripChars(place,[',','.', and so on]);

Upvotes: 1

Related Questions