Which loop type is better for situations where the number of iterations isn't predetermined?

The while loop is particularly suited for situations where the number of iterations is not known in advance. This loop continues to execute as long as the specified condition evaluates to true. It allows for an indefinite number of iterations, making it ideal for scenarios where the termination of the loop relies on a condition that may change during execution, such as user input or data that is being processed.

In contrast, the for loop is typically used when the number of iterations is known ahead of time, as it operates based on an initialization, a condition, and an increment/decrement statement. The do..while loop also requires a condition but evaluates it after the loop has executed at least once, which may not be suitable if the loop should not execute at all when the condition is false initially. Nested loops involve looping within other loops and typically are utilized in more complex situations, but they also require a predetermined structure in terms of the number of iterations. Thus, for the need of an unpredictable iteration count, the while loop is the most suitable choice.