Question

The ______ loop always iterates at least once.

Short answer

Answer: The do-while loop is guaranteed to iterate at least once.

Step-by-step solution

Identifying types of loops

There are three common types of loops in most programming languages: 1. For loop 2. While loop 3. Do-while loop

Analyzing the For loop

The for loop is used for iterating over a sequence (that is either a list, tuple, dictionary, set, or string) with a predetermined number of iterations. Here is an example of a for loop structure: ``` for i in range(n): // Code to be executed ``` This loop will iterate n times. If n is 0 or negative, the loop will not execute at all.

Analyzing the While loop

The while loop in the programming language allows the code inside the loop to be executed repeatedly as long as the given condition is `True`. Here is an example of a while loop structure: ``` while condition: // Code to be executed ``` This loop will only execute as long as the given condition is satisfied. If the condition is `False` initially, the loop will not execute any iterations.

Analyzing the Do-While loop

The do-while loop is a variation of the while loop, which tests the condition after executing the statements. Here is an example of a do-while loop structure: ``` do { // Code to be executed } while (condition); ``` This loop is guaranteed to execute at least once because the code inside the loop runs before the condition is tested.

Answer

The loop that always iterates at least once is the do-while loop.