I've tried the following code without success.
string.remove[index];
string.insert[index];
Can anyone suggest how can I correct this code?
Add a comment
|
3 Answers
Just do this:
stringVariable[index] := 'A';
4 Comments
Darthman
It's valid for most of delphi, but that kind of code now is depricated. If you need to change string, you must use TStringBuilder class for that kind of work.
Remy Lebeau
@DavidHeffernan: it is not deprecated just yet, but it may be in the not-too-distant future. The current version already issues warnings about it now.
Ken White
@Remy: I just tested in XE4, with
Test := 'Testing'; Test[3] := 'x'; WriteLn(Test); ReadLn;, and don't get any compiler warning in a Win32 console app.Remy Lebeau
It is not deprecated in the Windows/OSX compilers yet, but it is deprecated in the iOS mobile compiler and documented as such: "the Delphi mobile compilers emit the warning W1068 Modifying strings in place may not be supported in the future (Delphi). At some point, this warning is to be replaced by an error"
You can directly access a string like it was a character array in Delphi:
MyString[Index] := NewChar;
For multiple character deletions and inserts, the System unit provides Delete and Insert:
System.Delete(MyString, Index, NumChars);
System.Insert(NewChars, MyString, Index);
Recent versions of Delphi provide the helper functions to string:
MyString := MyString.Remove(3, 1);
MyString := MyString.Insert(3, NewChars);
Once again, please read the tutorials I've referred you to twice previously. This is a very basic Pascal question that any of them would have answered for you.
4 Comments
diegoaguilar
I TRIED and compiler gives me fail!
Blorgbeard
@Diego no it does not "give you fail!" - it gives you a specific error message, which you should READ and post in your original question if you don't understand!
Ken White
Would the downvoter please explain what's wrong with my answer, both so I can correct it and so I can see the problem? Thanks.
Ken White
@David: Not that important, and usually I just ignore them. I actually thought I'd covered the bases pretty well here, though, so I was just curious what I'd missed. I still don't see anything wrong, so it's most likely either someone being extremely petty or someone getting revenge for something.
Here is another way to do it. Have fun with Delphi
FUNCTION ReplaceCharInPos(CONST Text: String; Ch: Char; P: Integer): String;
VAR Lng: Integer; left, Right: String;
BEGIN
Lng:= Length(Text);
IF Lng = 0 THEN
Result:= ''
ELSE IF (P < 1) OR (P > Lng) THEN
Result:= Text
ELSE IF P = 1 THEN
Result:= Ch + Copy(Text, 2, Lng - 1)
ELSE IF P = Lng THEN
Result:= Copy(Text, 1, Lng - 1) + Ch
ELSE BEGIN
Left:= Copy(Text, 1, P - 1);
Right:= Copy(Text, P + 1, Lng - P);
Result:= Left + Ch + Right;
END;
END;
