Programming is one of those fields which is nice about outdated information. You can take any C program on SO right now and compile it in Borland C 2.01 and it will likely run.
C, as a language, has not changed much over the years.
Some languages are still evolving, such as C# and their runtimes evolve as well, for instance the JVM supports a few important features now that it didn't a decade ago.
However, that version specific information is captured, largely, in version numbers, and those can often be found on individual questions, or if nothing else can be inferred by the date of the posting.
Further, in almost all cases these are backwards compatible, so the advice given now for a specific problem may not be the latest and greatest, but it will likely still work.
As much as the industry changes day to day, it's remarkably robust in terms of information age and relevance.