Editing Infinite loop (section)

===Unintentional looping===
[[File:Infinite loop BSOD.jpg|thumb|A [[blue screen of death]] on [[Windows XP]]. "The [[device driver]] got stuck in an infinite loop."]]
Most often, the term is used for those situations when this is not the intended result; that is, when this is a [[software bug|bug]].<ref>{{cite web
 |url=https://nyxcrossword.com/2013/10/1013-13-new-york-times-crossword.html
 |title=New York Times Crossword Answers
 |quote=computing .. a defect .. which .. to loop
 |date=October 13, 2013
 |access-date=January 22, 2020
 |archive-date=August 2, 2020
 |archive-url=https://web.archive.org/web/20200802040416/https://nyxcrossword.com/2013/10/1013-13-new-york-times-crossword.html
 |url-status=live
 }}</ref> Such errors are most common by novice programmers, but can be made by experienced programmers also, because their causes can be quite subtle.

One common cause, for example, is that a programmer intends to iterate over sequence of nodes in a [[data structure]] such as a [[linked list]] or [[Tree (data structure)|tree]], executing the loop code once for each node. Improperly formed links can create a ''reference loop'' in the data structure, where one node links to another that occurs earlier in the sequence. This makes part of the data structure into a [[Ring (data structure)|ring]], causing naive code to loop forever.

While most infinite loops can be found by close inspection of the code, there is no general method to determine whether a given program will ever halt or will run forever; this is the [[undecidable problem|undecidability]] of the [[halting problem]].<ref>{{cite web|url=https://www.geeksforgeeks.org/halting-problem-in-theory-of-computation|title=Halting Problem in Theory of Computation|date=3 October 2018|access-date=22 January 2020|archive-date=9 August 2020|archive-url=https://web.archive.org/web/20200809100104/https://www.geeksforgeeks.org/halting-problem-in-theory-of-computation/|url-status=live}}</ref>