PHP preg_replace code convert to Delphi

depends on your delphi version
as of a certain version there is unit RegularExpressions

do you have test case in php ?
sample input and output ?

technically it's just this :

unit uMain;

interface

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls;

type
  TForm1 = class(TForm)
    mmoInput: TMemo;
    mmoOutput: TMemo;
    btnParse: TButton;
    procedure btnParseClick(Sender: TObject);
  end;

var
  Form1: TForm1;

implementation

uses System.RegularExpressions;

{$R *.dfm}

procedure TForm1.btnParseClick(Sender: TObject);
var R: TRegEx;
begin
  R.Create('/\s+([\w]{3,18}:)/u');
  mmoOutput.Text := R.Replace(mmoInput.Text, '');
end;

end.

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that's besides any differences between php and delphi regex
there is slight differences... but you'd have to test to find if the differences have impact
http://www.regular-expressions.info/index.html

Delphi 10.1 Berlin

this is the input :
'Alapadatok:      Sebesség:   300Mbps    Otthoni:   Igen    Irodai:   Igen    Szabvány :   802.11a/b/g/n    802.11AC :   Igen    QoS :   Igen    WMM :   Igen    Gigabit Mbps LAN :   Igen    IPv6 :   Igen'

The output must be the following:
'igen  szabvány 802.11a/b/g/n 802.11ac qos wmm gigabit mbps lan ipv6'

This is one of those questions that would benefit from having good test data!

I don't have test data or a Delphi system to make the tests, but I can explain the regular expression.  HTH, ~Ray

<?php
/**
 * http://php.net/manual/en/reference.pcre.pattern.modifiers.php
 * http://php.net/manual/en/function.preg-replace.php
 */
error_reporting(E_ALL);

// FROM THE POST AT EE:
// $src =  preg_replace("/\s+([\w]{3,18}:)/u","",$src);

// ANNOTATED REGULAR EXPRESSION
$rgx
= '/'                 // REGEX DELIMITER
. '\s+'               // ONE OR MORE CHARACTERS OF WHITESPACE
. '('                 // START CAPTURE GROUP
. '['                 // START CHARACTER CLASS
. '\w'                // CHARACTER CLASS = "WORDS"
. ']'                 // ENDOF CHARACTER CLASS
. '{3,18}'            // LENGTH IS 3 TO 18, INCLUSIVE
. ':'                 // FOLLOWED BY A COLON
. ')'                 // ENDOF CAPTURE GROUP
. '/'                 // REGEX DELIMITER
. 'u'                 // FLAG MODIFIER - UTF-8
;

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It looks like this regular expression does not work correctly in PHP.  Maybe there is more to this process that we are not seeing here?  Here's a test case using the inputs and outputs posted above.
https://www.iconoun.com/demo/temp_rt.php

<?php // demo/temp_rt.php
/**
 * https://www.experts-exchange.com/questions/28993289/PHP-preg-replace-code-convert-to-Delphi.html
 *
 * http://php.net/manual/en/reference.pcre.pattern.modifiers.php
 * http://php.net/manual/en/function.preg-replace.php
 *
 * From the post at E-E:
 * $src =  preg_replace("/\s+([\w]{3,18}:)/u","",$src);
 */
error_reporting(E_ALL);

// MAKE SURE THAT PHP WORKS WITH UTF-8
mb_internal_encoding('UTF-8');
mb_regex_encoding('UTF-8');


// ANNOTATED REGULAR EXPRESSION
$rgx
= '/'                 // REGEX DELIMITER
. '\s+'               // ONE OR MORE CHARACTERS OF WHITESPACE
. '('                 // START CAPTURE GROUP
. '['                 // START CHARACTER CLASS
. '\w'                // CHARACTER CLASS = "WORDS"
. ']'                 // ENDOF CHARACTER CLASS
. '{3,18}'            // LENGTH IS 3 TO 18, INCLUSIVE
. ':'                 // FOLLOWED BY A COLON
. ')'                 // ENDOF CAPTURE GROUP
. '/'                 // REGEX DELIMITER
. 'u'                 // FLAG MODIFIER - UTF-8
;

// TEST STRING
$src = 'Alapadatok:      Sebesség:   300Mbps    Otthoni:   Igen    Irodai:   Igen    Szabvány :   802.11a/b/g/n    802.11AC :   Igen    QoS :   Igen    WMM :   Igen    Gigabit Mbps LAN :   Igen    IPv6 :   Igen';

// DESIRED OUTPUT
$out = 'igen  szabvány 802.11a/b/g/n 802.11ac qos wmm gigabit mbps lan ipv6';

// TRY
$new = preg_replace($rgx, NULL, $src);

// SHOW THE WORK
echo '<pre>';
echo PHP_EOL . $rgx;
echo PHP_EOL . $src;
echo PHP_EOL . $out;
echo PHP_EOL . $new;

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Outputs:

/\s+([\w]{3,18}:)/u
Alapadatok:      Sebesség:   300Mbps    Otthoni:   Igen    Irodai:   Igen    Szabvány :   802.11a/b/g/n    802.11AC :   Igen    QoS :   Igen    WMM :   Igen    Gigabit Mbps LAN :   Igen    IPv6 :   Igen
igen  szabvány 802.11a/b/g/n 802.11ac qos wmm gigabit mbps lan ipv6
Alapadatok:   300Mbps   Igen   Igen    Szabvány :   802.11a/b/g/n    802.11AC :   Igen    QoS :   Igen    WMM :   Igen    Gigabit Mbps LAN :   Igen    IPv6 :   Igen

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The PHP solution is ok, only the first word (Alapadatok:) not replace because not have whitespace.
But the delphi code is not replace any word.

it won't replace anything in delphi

i was searching for the equivalent forward slash ... but hadn't found it yet.
based on ray's text, i now know it's not required

the /u at the end is not required either

the character class [ can be skipped and the end too ]

the capture group ... what do you want with that ?

The forward slash regex delimiter is not required in some PHP work, too.  The UTF-8 modifier may not be needed in this PHP regex because there are not any UTF-8 characters in the expression.  If there are, PHP would recommend mb_ereg_ functions instead.

to have something to play with, just add an edit1.Text
and change the function to this:

procedure TForm1.btnParseClick(Sender: TObject);
var R: TRegEx;
begin
  R.Create(edit1.Text); // '\s+\w{3,18}:');
  mmoOutput.Text := R.Replace(mmoInput.Text, '');
end;

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your output sample doesn't match your regex

anyway ...
in delphi i get closest to it with this regex:
\s?\w{3,18}:

unit uMain;

interface

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, System.RegularExpressions;

type
  TForm1 = class(TForm)
    mmoInput: TMemo;
    mmoOutput: TMemo;
    btnParse: TButton;
    Edit1: TEdit;
    procedure btnParseClick(Sender: TObject);
  private
    function MatchReplace(const Match: TMatch): string;
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.btnParseClick(Sender: TObject);
var R: TRegEx;
  mc: TMatchCollection;
begin
  R.Create(edit1.Text); // '\s+\w{3,18}:');
  mc := R.Matches(mmoInput.Text);
  mmoOutput.Text := R.Replace(mmoInput.Text, MatchReplace);
end;

function TForm1.MatchReplace(const Match: TMatch): string;
begin
  Result := '';
end;

end.

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Geert Gruwez

your regex is very close to the perfect.
The only problem is,
they cut the words with no space before the ":" like this : Alapadatok:
and cut the words with space before the ":" like this : Szabvány :

I want cut only the words with no space before the ":" like this : Alapadatok:

!!!don't cut the words with space before the ":" like this : Szabvány :!!!

can you work on it please ?

if you can provide an accurate sample of what your regex in php gives
actually multiple samples would be nice.

you typed your output, you didn't just copy .

• the case of the letters was wrong
• the 300Mb was missing
• etc ...

so if you can't give a valid output, it's just guessing.