RegEx in Delphi

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RegEx in Delphi

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#1 by (5 votes)

4

A help with regular expressions in Delphi 10 please. I need to check the following in string :

Size ranging from a minimum of 6 characters to a maximum of 20 characters;

Type of characters: a-z or A-Z or 0-9 or _ (underline character);

The allowed characters can be in any position and in any quantity (up to the limit of the string, of course);

Examples

VALID STRINGS :

AaaaaaaaBCCcc654_qq
1111s123AaBCcc654_qq
____ds4___xx
12345_123

INVALID STRINGS :

12345-123            (tem hífen)
asdkdn  092834sdfdf  (tem espaco em branco)
$123.0               (tem "$" e ".")

I tried things like these, but they did not work:

var ret: TMatch;
begin
   ret := TRegEx.Match(Edit1.Text, '([a-z]*[A-Z]*[0-9]*[-]?)', [roIgnoreCase]);

or

   ret := TRegEx.Match(Edit1.Text, '(\w*)', [roIgnoreCase]);

regex delphi

asked by anonymous 04.12.2017 / 15:25

1 answer

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score 5 · Accepted Answer

\w home a-z , A-Z , 0-9 or _ .
Just repeat 6 to 20 times, that's \w{6,20}
From the beginning of the string ^ to the end of the string $ .

Then:

^\w{6,20}$

And in this case, it's easier to use the TRegEx.IsMatch ()

Code:

{$APPTYPE CONSOLE}

uses
    System.RegularExpressions;

var texto: string;

begin
    texto := 'AaaaaaaaBCCcc654_qq';

    if TRegEx.IsMatch(texto, '^\w{6,20}$') then
        begin
            Writeln(texto, ' é válido');
        end
    else
        begin
            Writeln(texto, ' não é válido');
        end;
end.