Counting the total number of theorems

Question

I have:

\usepackage{amsthm}
\newtheorem{problem}{Problem}
....
\begin{problem}...\end{problem}...
...
\begin{problem}...\end{problem}...

In the first page of the document, how can I know the number of the problem environments used in the document? That is, I want to know the value of the last problem counter.

You are looking for \value{problem} or maybe \the\value{problem} depending on where you want to use it. — Seamus, Mar 13 '12 at 16:30
@Seamus I don't want to sound harsh, but wouldn't \the\value{problem} return 0 at the beginning of the document no matter the number of problems? — yo', Mar 13 '12 at 16:42
@tohecz Perhaps I misunderstood the question, but I took it to be about accessing the number of problems so far, at a point in the document. If you want to know the value of the problem counter at the end of the document, then my suggestion will work. — Seamus, Mar 13 '12 at 16:54
@tohecz Seamus says "Perhaps I misunderstood the question …" — Seamus, Mar 13 '12 at 17:39
@Seamus and tohecz: Chang says "Thank you for your answers." — Chang, Mar 13 '12 at 17:52

score 13 · Accepted Answer · answered Mar 13 '12 at 16:36

13

The following code uses the .aux file for that. It provides a macro \total@problems that sets \totalproblems to its parameter. And calls this macro at the end of document to store the value of counter problem. You need to run twice, and there is 0 stored at the first run.

\documentclass{article}

\usepackage{amsthm}
\newtheorem{problem}{Problem}

% STARTS HERE
\makeatletter
\AtEndDocument{\write\@auxout{\protect\total@problems{\arabic{problem}}}}
\def\total@problems#1{\global\def\totalproblems{#1}}
\total@problems{0}
\makeatother
% ENDS HERE

\begin{document}

Number of problems: \totalproblems

....
\begin{problem}...\end{problem}...
...
\begin{problem}...\end{problem}

\end{document}

answered Mar 13 '12 at 16:36

yo'

51,322

Thanks. It works good. I wrote There are \totalproblems problems., and it returns There are 5problems. What is a good workaround for the spacing without manually adding a space? – Chang Mar 13 '12 at 16:47
1

@Chang the manual space is simply a matter of writing \ (that is, backslash, space) There are \totalproblems\ problems. Or look at the xspace package. – Seamus Mar 13 '12 at 16:55
@Seamus Yes, I know \. But why should \totalproblems problems not be 5 problems? – Chang Mar 13 '12 at 17:00
2

The package totcount does something similar. – egreg Mar 13 '12 at 17:03
3

@Chang because the space after a macro is ignored. – Seamus Mar 13 '12 at 17:03
1

@Chang An alternative to Seamus's solution is \totalproblems{} problems – yo' Mar 13 '12 at 17:06
@egreg How can the totcount package be used to solve this problem? – user4514 Mar 11 '13 at 09:39
@user4514 I've added an answer – egreg Mar 11 '13 at 10:27
@egreg Perfect! – user4514 Mar 11 '13 at 18:44

score 11 · Answer 2 · answered Mar 11 '13 at 10:21

11

The package totcount provides a very efficient solution. It's sufficient to register the counter to the list of "total counters".

\documentclass{article}

\usepackage{totcount}

\newtheorem{problem}{Problem}
\regtotcounter{problem} % register the counter for getting the total

\begin{document}

Number of problems: \total{problem}

\begin{problem}
A
\end{problem}

\begin{problem}
B
\end{problem}

\end{document}

Using \total{problem} will print the required number; LaTeX will warn if another run is needed because of changes in the total.

answered Mar 11 '13 at 10:21

egreg

1,121,712

the first time I compile it gives me ?? and the second time it shows 0. Why? I have written more than 100 problems. – yngabl Jan 16 '18 at 20:13
1

@yngabl I'm sorry, but I get 2 with the example code. Maybe you have some different setting. – egreg Jan 16 '18 at 21:23

Counting the total number of theorems

2 Answers2

Linked