Infinite Loops

Emergence of infinite loops

One common programming mistake is to create an infinite loop. An infinite loop refers to a loop, which under certain valid (or at least plausible) input, will never exit.

Note: Beginning programmers should be careful to examine all the possible inputs into a loop to ensure that for each such set of inputs, there is an exit condition that will eventually be reached.

Compilers, debuggers, and other programming tools can only help the programmer so far in detecting infinite loops.

Note: In the fully general case, it is not possible to automatically detect an infinite loop. This is known as the halting problem.

While the halting problem is not solvable in the fully general case, it is possible to determine whether a loop will halt for some specific cases.

Uses of infinite loops

The conditions when infinite loops can be extremely useful are the following:

• When continuous input is required to the program or system, and it has to respond accordingly without stopping.

• When we do not know the exit condition, some calculations need to be performed inside the loop, which will decide when to exit or terminate the loop.

Example of infinite loop

Below is an example of an infinite loop.

Note: You will get an error when you try to run the code below because an infinite number of print statements cannot be shown here.