Delphi-如何从字符串中提取数字？

Question

I was developing a program that validate a CPF, a type of document of my country. I already did all the math. But in the input Edit1, the user will insert like:

123.456.789-00

I have to get only the numbers, without the hyphen and the dots, to my calcs worth.

I'm newbie with Delphi, but I think that's simple. How can I do that? Thanks for all

Answer 1

You can use

text := '123.456.789-00'
text := TRegEx.Replace(text, '\D', '')

Here, \\D matches any non-digit symbol that is replaced with an empty string.

Result is 12345678900 (see regex demo ).

Answer 2

Using David's suggestion, iterate your input string and remove characters that aren't numbers.

{$APPTYPE CONSOLE}

function GetNumbers(const Value: string): string;
var
  ch: char;
  Index, Count: integer;
begin
  SetLength(Result, Length(Value));
  Count := 0;      
  for Index := 1 to length(Value) do
  begin
    ch := Value[Index];
    if (ch >= '0') and (ch <='9') then
    begin
      inc(Count);
      Result[Count] := ch;
    end;
  end;
  SetLength(Result, Count);
end;

begin
  Writeln(GetNumbers('123.456.789-00'));
  Readln;
end.