Argthtjtr

Here is MWE:

documentclass{scrartcl}

usepackage{adforn}





renewcommand{sectionlinesformat}[4]{%

        ifstr{#1}{section}{%

               {adforn{30} {#3}. {#4} adforn{58}}

        }

    {{hskip#2#3}{#4}}%

}makeatother



begin{document}



section{ABC}



end{document} 

The output is this:

I want it will be: 1. ABC and not 1 . ABC (no space between the "1" and the ".").

It is possible? and if it's possible, how can I do it?

Thank you!

The macro sectionformat contains an enskip at the end. You can redefine it without that:

documentclass{scrartcl}

usepackage{adforn}



defsectionformat{thesectionautodot}% enskip

renewcommand{sectionlinesformat}[4]{%

        ifstr{#1}{section}{%

               {adforn{30} {#3}. {#4} adforn{58}}

        }

    {{hskip#2#3}{#4}}%

}makeatother



begin{document}



section{ABC}



end{document}

You should reduce group braces to a minimum and add the . either to the sectionformat:

documentclass{scrartcl}

usepackage{adforn}



renewcommand*{sectionformat}{thesection.enskip}% replaced autodot by .

renewcommand{sectionlinesformat}[4]{%

  ifstr{#1}{section}%

    {adforn{30} #3#4 adforn{58}}%

    {hskip#2#3#4}%

}makeatother



begin{document}



section{ABC}



end{document} 

or select numbers=withdot to add the dot to all section levels:

documentclass[numbers=enddot]{scrartcl}

usepackage{adforn}



renewcommand{sectionlinesformat}[4]{%

  ifstr{#1}{section}%

    {adforn{30} #3#4 adforn{58}}%

    {hskip#2#3#4}%

}



begin{document}



section{ABC}



end{document} 

Both examples result in:

Note: You should not combine a autodot in sectionformat with a hard coded . (neither in autodot nor on sectionlinesformat where it is misplaced by specification), because this could result in two dots.

Please have a look to the KOMA-Script manual for the default of sectionformat and the meaning of numbers=withdot, sectionformat and autodot.

BTW: The makeatother in your example is also not necessary and should be removed (so I did).

Off-Topic: You should also avoid possible spurious white spaces by newlines after } or { and by real spaces in the middle of the code.

As a comment claims that this does not work with hebrew:

documentclass[numbers=enddot]{scrartcl}

usepackage{polyglossia}

setmainlanguage{hebrew}

newfontfamilyhebrewfont[Script=Hebrew]{David CLM}

newfontfamilyhebrewfonttt[Script=Hebrew]{Miriam Mono CLM}

newfontfamilyhebrewfontsf[Script=Hebrew]{Simple CLM}

usepackage{adforn}



renewcommand{sectionlinesformat}[4]{%

  ifstr{#1}{section}%

    {adforn{30} #3#4 adforn{58}}%

    {hskip#2#3#4}%

}



begin{document}



section{גדה}



end{document} 

and

documentclass{scrartcl}

usepackage{polyglossia}

setmainlanguage{hebrew}

newfontfamilyhebrewfont[Script=Hebrew]{David CLM}

newfontfamilyhebrewfonttt[Script=Hebrew]{Miriam Mono CLM}

newfontfamilyhebrewfontsf[Script=Hebrew]{Simple CLM}

usepackage{adforn}



renewcommand*{sectionformat}{thesection.enskip}% replaced autodot by .

renewcommand{sectionlinesformat}[4]{%

  ifstr{#1}{section}%

    {adforn{30} #3#4 adforn{58}}%

    {hskip#2#3#4}%

}



begin{document}



section{גדה}



end{document} 

both result in:

which seem to be correct for using RL.