Condition within condition

Question

Consider the following logical satatements:

If \conditionA != 100 and \conditionB != 100 do ``Something~A''
If \conditionA != 100 and \conditionB  = 100 do ``Something~B''
If \conditionA  = 100 and \conditionB != 100 do ``Something~C''
If \conditionA  = 100 and \conditionB  = 100 do ``Something~D''

How do I translate this into a

\ifnum ... do ... \else do ... \fi

type of argument?

I've found this post by Joseph Wright but I can't figure out how to modify the example to make it do what I would like.

P.S. Feel free to add missing tags.

Answer 1

With LaTeX3 syntax the command is expandable, if needed:

\documentclass{article}
\usepackage{expl3}
\ExplSyntaxOn

\int_new:N \l_svend_condition_A_int
\int_new:N \l_svend_condition_B_int

\cs_new:Npn \svend_check:
 {
  \int_compare:nTF { \l_svend_condition_A_int = 100 }
   {
    \int_compare:nTF { \l_svend_condition_B_int = 100 }
     {
      \typeout{Both~are~100}
     }
     {
      \typeout{A~is~100,~B~is~not~100}
     }
   }
   {
    \int_compare:nTF { \l_svend_condition_B_int = 100 }
     {
      \typeout{A~is~not~100,~B~is~100}
     }
     {
      \typeout{A~is~not~100,~B~is~not~100}
     }
   }
 }

\int_set:Nn \l_svend_condition_A_int {100}
\int_set:Nn \l_svend_condition_B_int {100}
\svend_check:
\int_set:Nn \l_svend_condition_A_int {100}
\int_set:Nn \l_svend_condition_B_int {101}
\svend_check:
\int_set:Nn \l_svend_condition_A_int {101}
\int_set:Nn \l_svend_condition_B_int {100}
\svend_check:
\int_set:Nn \l_svend_condition_A_int {101}
\int_set:Nn \l_svend_condition_B_int {101}
\svend_check:

Here's the output on the terminal:

Both are 100
A is 100, B is not 100
A is not 100, B is 100
A is not 100, B is not 100

---

With traditional syntax it's just the same:

\documentclass{article}

\newcommand{\Check}[2]{%
  \ifnum#1=100
    \ifnum#2=100
      \typeout{\#1 is 100, \#2 is 100}%
    \else
      \typeout{\#1 is 100, \#2 is not 100}%
    \fi
  \else
    \ifnum#2=100
      \typeout{\#1 is not 100, \#2 is 100}%
    \else
      \typeout{\#1 is not 100, \#2 is not 100}%
    \fi
  \fi
}

\Check{100}{100}
\Check{101}{100}
\Check{100}{101}
\Check{101}{101}

Here's the output:

\#1 is 100, \#2 is 100
\#1 is not 100, \#2 is 100
\#1 is 100, \#2 is not 100
\#1 is not 100, \#2 is not 100

Answer 2

For completeness, here's an etoolbox implementation:

\documentclass{article}
\usepackage{etoolbox}% http://ctan.org/pkg/etoolbox
\newcommand{\Test}[2]{%
  \ifnumequal{#1}{100}{%
    \ifnumequal{#2}{100}{%
      First arg = 100; Second arg = 100%
    }{%
      First arg = 100; Second arg != 100%
    }}{%
    \ifnumequal{#2}{100}{%
      First arg !=100; Second arg = 100%
    }{%
      First arg !=100; Second arg != 100%
    }}%      
}
\begin{document}

\Test{100}{100} \par
\Test{ 99}{100} \par
\Test{101}{101} \par
\Test{100}{101}

\end{document}

Answer 3

Does the solution have to be at the level of TeX-primitives? If not, I suppose you could load the ifthen package and execute something like this:

\ifthenelse{\NOT\conditionA=100}%
   {\ifthenelse{\NOT\ConditionB=100}%
      {"Do SomethingA"}%
      {"Do SomethingB"}}%
   {\ifthenelse{\NOT\ConditionB=100}%
      {"Do SomethingC"}%
      {"Do SomethingD"}}

Here, I'm assuming that \ConditionA and \ConditionB evaluate/expand to integers. If that's not the case, the \NOT... branch will always prevail.

---

Addendum: Assuming that the macros \ConditionA and \ConditionB are expandable and evaluate to integers, you could also employ the \ifnum "primitive" control sequence. Note that for the sake of simplicity equality rather than inequality is tested; hence the "Do" sequence is reversed relative to the earlier example.

\ifnum\conditionA=100%
   \ifnum\conditionB=100
      {"Do SomethingD"}
      \else {"Do SomethingC"}
   \fi
\else
   \ifnum\conditionB=100
      {"Do SomethingB"}
      \else {"Do SomethingA"}
   \fi
\fi

Answer 4

For completeness, the (soon-to-be-completely-deprecated-hopefully) TeX-core solution, fully expandable, like the @egreg's one:

\long\def\FirstOfFour#1#2#3#4{#1}
\long\def\SecondOfFour#1#2#3#4{#2}
\long\def\ThirdOfFour#1#2#3#4{#3}
\long\def\FourthOfFour#1#2#3#4{#4}
\def\HundredTest#1#2{%
  \ifcase\numexpr
    \ifnum #1=100 1\else0\fi +
    \ifnum #2=100 2\else0\fi \relax
    \expandafter\FirstOfFour\or
    \expandafter\SecondOfFour\or
    \expandafter\ThirdOfFour\or
    \expandafter\FourthOfFour
  \fi
}

\HundredTest{100}{111}{NN}{YN}{NY}{YY} %YN
\HundredTest{100}{100}{NN}{YN}{NY}{YY} %YY
\HundredTest{111}{111}{NN}{YN}{NY}{YY} %NN
\HundredTest{111}{100}{NN}{YN}{NY}{YY} %NY

\bye