What is the key difference between the working of while and do-while loops in C?

Explanation:

Key Difference Between While and Do-While Loops

Definition: The key difference between a while loop and a do-while loop lies in the evaluation of the loop condition. A while loop evaluates the condition before executing the loop body, whereas a do-while loop evaluates the condition after executing the loop body. This means that the do-while loop guarantees at least one execution of the loop body, irrespective of whether the condition is true or false.

Working Principle:

• While Loop: The condition is checked at the beginning of the loop. If the condition evaluates to true, the loop body is executed; otherwise, the loop terminates. This implies that if the condition is initially false, the loop body will not execute even once.
• Do-While Loop: The loop body is executed first, followed by the evaluation of the condition. If the condition evaluates to true, the loop repeats; otherwise, it terminates. This ensures that the loop body is always executed at least once, regardless of the condition.

Advantages of Do-While Loop:

• Guarantees at least one execution of the loop body, which is useful in scenarios where the loop body must run at least once before checking the condition.
• Useful for input validation or menu-driven programs, where user input needs to be processed at least once.

Advantages of While Loop:

• More straightforward in cases where the loop condition determines whether the loop body should execute.
• Does not execute the loop body unnecessarily if the condition is false initially, saving computational resources.

Correct Option Analysis:

The correct option is:

Option 4: A while loop evaluates the condition before executing the loop body, whereas a do-while loop evaluates the condition after executing the loop body.

This option accurately captures the fundamental difference between the two types of loops. The while loop checks the condition at the beginning, ensuring the loop body is not executed if the condition is false initially. On the other hand, the do-while loop executes the loop body once before checking the condition, ensuring at least one execution