Mega Code Archive
How to check if a String is numeric
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Title: How to check if a String is numeric
{1.}
function IsStrANumber(const S: string): Boolean;
var
P: PChar;
begin
P := PChar(S);
Result := False;
while P^ #0 do
begin
if not (P^ in ['0'..'9']) then Exit;
Inc(P);
end;
Result := True;
end;
{2.}
function IsStrANumber(const S: string): Boolean;
begin
Result := True;
try
StrToInt(S);
except
Result := False;
end;
end;
Usage Example:
procedure TForm1.Button1Click(Sender: TObject);
begin
if IsStrANumber(edit1.Text) = True then
ShowMessage('String contains only numbers!');
end;
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