Delphi 7
How do i remove leading zeros in a delphi string?
Example:
00000004357816
function removeLeadingZeros(ValueStr: String): String
begin
result:=
end;
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6 Answers
Code that removes leading zeroes from '000'-like strings correctly:
function TrimLeadingZeros(const S: string): string;
var
I, L: Integer;
begin
L:= Length(S);
I:= 1;
while (I < L) and (S[I] = '0') do Inc(I);
Result:= Copy(S, I);
end;
5 Comments
lkessler
This is what I would have done. Much more efficient than David's answer.
Chris Thornton
Nice solution. From a practicality standpoint, it will be more useful if the trim char ('0' in this case) is passed in as a parameter, then it can trim any char.
Andreas Rejbrand
I am not sure if this is "much more efficient than David's answer", but it is slightly more elegant and, most importantly, doesn't show the bug in David's code.
David Heffernan
+1 I wouldn't worry too much about efficiency. Getting it right is more important! For what it's worth there's no real difference in efficiency.
datatraveller1
Calling this function for
0000.89 results in .89 but 0.89 would be better. So I think the line no. 7 could be changed to: while (I < L) and (S[I] = '0') and (S[I+1] = '0') do Inc(I);function removeLeadingZeros(const Value: string): string;
var
i: Integer;
begin
for i := 1 to Length(Value) do
if Value[i]<>'0' then
begin
Result := Copy(Value, i, MaxInt);
exit;
end;
Result := '';
end;
Depending on the exact requirements you may wish to trim whitespace. I have not done that here since it was not mentioned in the question.
Update
I fixed the bug that Serg identified in the original version of this answer.
answered May 2, 2011 at 12:13
David Heffernan
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8 Comments
IElite
what if there is a zero in the string (not necessary in the beginning? Example: 00000004307016
David Heffernan
That's fine, the code just removes leading zeros as you requested. Your example will return '4307016' from this code.
Jørn E. Angeltveit
@Shane, I think you should read the code once more. It finds the first non-0 char and returns the rest of the string.
IElite
I read it, i didn't understand it. I made my comment then i tested it. It errored out a couple of times cause of missing semi-colons, and the addition of an extra "End"....but i figured it out and got it to compile and was able to test
kludg
Hmm... ShowMessage(removeLeadingZeros('000'));
|
Use JEDI Code Library to do this:
uses JclStrings;
var
S: string;
begin
S := StrTrimCharLeft('00000004357816', '0');
end.
1 Comment
Ken White
You should probably mention (in case the OP doesn't know) that this requires the JEDI Code Library (JCL), and provide a link.
Probably not the fastest one, but it's a one-liner ;-)
function RemoveLeadingZeros(const aValue: String): String;
begin
Result := IntToStr(StrToIntDef(aValue,0));
end;
Only works for numbers within the Integer range, of course.
1 Comment
Disillusioned
Also only if the string is actually a number. I.e. no alpha chars at all.
Searching for this in 2021 there is a much better solution that I found now and that is using the TStringHelper function TrimLeft as follows
myString := myString.TrimLeft(['0']);
see here for more on the documentation http://docwiki.embarcadero.com/Libraries/Sydney/en/System.SysUtils.TStringHelper.TrimLeft
1 Comment
Kira Resari
This should be the accepted answer as of 2021
Try this:
function TFrmMain.removeLeadingZeros(const yyy: string): string;
var
xxx : string;
begin
xxx:=yyy;
while LeftStr(xxx,1) = '0' do
begin
Delete(xxx,1,1);
end;
Result:=xxx;
end;
