When does an infinite loop occur?

• A. When the program terminates unexpectedly due to an error.
• B. When the ending condition will never evaluate to true.
• C. When the loop body executes too many times.
• D. When no exit condition is specified.

Answer: (B)

An infinite loop happens when the rule that ends the loop can never be satisfied, so the loop keeps running without ever reaching a stop point. This can occur if the loop’s terminating condition is never met, or if the condition is always true and there’s no other exit. For example, a loop written as while (true) { ... } will run forever unless something inside breaks out of it, and a loop where the control variable is never updated (while (i < 10) { ... } with i never changing) will also never terminate. The key idea is that the loop’s end condition cannot become false (or cannot be satisfied to exit) under normal execution. The other options describe termination due to an error, a finite number of iterations, or a structurally infinite loop due to no exit, but the common thread in an infinite loop is that the stopping condition can’t be reached.