# How to define a if-condition? [duplicate]

I found several entries about the fact that the ifthen package is obsolete. So my question is: how to define a condition check then? I have searched and I find several example for ifthenelse (contained in the ifthen) package OR the statement "ifthen package is obsolete".

-

## marked as duplicate by Peter Grill, Papiro, Masroor, Jubobs, GuidoAug 8 at 23:00

it is not obsolete –  Herbert May 6 '13 at 12:32
@Herbert I agree; maybe it's not the first choice any more, but it's easy and in some cases it's sufficient. Probably using xifthen in place of it is better anyway. –  egreg May 6 '13 at 13:01

It may be considered obsolete because there exist more modern variants and the package was not updated for a long time.

See for example http://www.ctan.org/pkg/etoolbox which uses e-TeX features.

Apart from the macros in ifthenelse being fragile, if you can handle that, you can just use them, no problem.

-
Welcome to TeX-SX! You may have a look at our starter page for a quick intro if you wish to familiarize yourself with our format. –  Claudio Fiandrino May 6 '13 at 12:47

I prefer

\def\something{}

\ifdefined\something
True
\else
False
\fi


to avoid the ifthen package.

The advantage of not using a package is that this approach can be used in files that are just \input by large document (for example TikZ images), when it cannot be guaranteed that a certain package is loaded.

-
Your code only shows how to check whether a macro is defined; I believe the OP's question is more general than that. –  Jubobs Aug 9 at 14:38
If you can influence setting the variable to true or false, you can also instead define or undefine it (\let\something\undefined) –  Scz Aug 11 at 16:30