What is the function of a while loop?

A while loop is a control structure that allows for the repeated execution of a block of code as long as a specified condition evaluates to true. This feature is particularly useful in scenarios where the number of iterations cannot be predetermined before the loop starts.

For instance, if a program needs to keep prompting a user for input until they provide a valid response, a while loop can continue to execute the prompt until the desired condition is met. The condition is checked before each iteration, ensuring that the loop continues as long as the condition holds true.

In contrast, executing code once would be the result of different constructs, such as a simple function call or a single statement execution. Creating an array of variables pertains to data storage rather than control flow, which is outside the while loop's purpose. Defining classes is specific to object-oriented programming and not related to the iterative functionality provided by a while loop. Thus, the main purpose of a while loop aligns with option B: to repeat code while a condition is true.