LoopingConstructs are a fundamental element of programming. Without looping (i.e. repeating) you couldn't abstract away anything. Looping is at the very least required in the hardware, e.g. in the form of a ProgramCounter. 

Looping can be realized by Recursion: See TailRecursionElimination and RecursionVsLoop.

There are quite a few pages here, but there is no category or else for them:
* http://www.c2.com/cgi/wiki?search=Recursion
* http://www.c2.com/cgi/wiki?search=Loop
* http://www.c2.com/cgi/wiki?search=Iterator

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CategoryProgrammingLanguage CategoryLoops