Trace values of parameters

Question

I would like to print the value of a register into the document for 'debugging' purposes. For counters I would use \arabic{myCounter}. But \abovedisplayskip is not a counter.

Answer 1

You can use \the to typeset a value of a dimension for example:

\the\abovedisplayskip

Answer 2

For debugging I often find \showthe to be more useful (as in \showthe\abovedisplayskip); it pauses the typesetting and displays the value on the console. For a LaTeX counter you would write

\showthe\c@foo

assuming you defined the counter as

\newcounter{foo}