LaTeX ÀÇ ÇÔ¼ö¿¡¼ Àμö¸¦ »ç¿ëÇÏ´Â °æ¿ì µðÆúÆ®ÆĶó¹ÌÅÍ ¸¦ »ç¿ëÇØ¾ß ÇÏ´Â °æ¿ì°¡ ÀÖ´Ù.
¹æ¹ý1 ¶
\newcommand\hello[2][\@empty]{%
\ifx#1\@empty%1 No option
\def\temp@val{1 : }%
\else% Option
\def\temp@val{#1 : }%
\fi%
}
¹æ¹ý2 ¶
\@ifnextchar ¸¦ ÀÌ¿ëÇؼ µÎ°³ÀÇ ÇÔ¼ö¸¦ ºÐ¸®Çؼ »ç¿ëÇÏ´Â ¹æ½Ä
\makeatletter
\def\PicTure{\@ifnextchar[\@pic@ture\@@pic@@ture}
\def\@pic@ture[#1]#2{\includegraphics[width=#1cm]{#2}}
\def\@@pic@@ture#1{\includegraphics{#1}}
\makeatother
DeleteMe \@ifnextcharÀÇ ¾²ÀÓ»õ¸¦ º¸¾ÆÇÏ´Ï Ç÷¹ÀÎÅØ¿¡¼ ¸¹ÀÌ(?) »ç¿ëÇÏ´Â \futurelet °ú \ifx¸¦ °áÇÕÇØ ³õÀº °Í°ú °°¾Æº¸ÀÔ´Ï´Ù. ·¹ÀÌÅØÀÌ ÆíÇϱä ÆíÇϳ׿ä.
\def\Com{\futurelet\testchar\MaybeOptArgCom}
\def\MaybeOptArgCom{\ifx[\testchar \let\next\OptArgCom
\else \let\next\NoOptArgCom \fi \next}
\def\OptArgCom[#1]#2{ ... }
\def\NoOptArgCom#1{ ... }