Looping is one of the most fundamental concepts in any programming language, allowing tasks to be repeated until certain conditions are met. For those looking to test or enhance their knowledge, we’ve assembled a set of Multiple Choice Questions (MCQs) related to Java loops.
1. Which loop construct in Java is best suited when the number of iterations is known?
Answer:
Explanation:
The for loop in Java is used when the number of iterations is known or can be determined beforehand.
2. What is the purpose of the continue statement in a loop?
Answer:
Explanation:
The continue statement in Java is used to skip the current iteration of a loop and move to the next iteration.
3. Which loop construct in Java is best suited when the number of iterations is unknown?
Answer:
Explanation:
The while loop in Java is used when the number of iterations is unknown or depends on a certain condition.
4. What is the key difference between a while loop and a do-while loop in Java?
Answer:
Explanation:
The key difference between a while loop and a do-while loop in Java is the timing of the condition check. In a while loop, the condition is checked before the loop body is executed, whereas in a do-while loop, the condition is checked after the loop body is executed.
5. Which loop construct guarantees that the loop body is executed at least once?
Answer:
Explanation:
The do-while loop in Java guarantees that the loop body is executed at least once, as the condition is checked after the loop body is executed.
6. What is an infinite loop?
Answer:
Explanation:
An infinite loop in Java is a loop that never terminates naturally unless interrupted externally or using a break statement.
7. Which statement is used to exit a loop prematurely?
Answer:
Explanation:
The break statement in Java is used to exit a loop prematurely and continue with the execution of the code outside the loop.
8. Which loop construct is best suited for iterating over an array or a collection?
Answer:
Explanation:
The for loop in Java is best suited for iterating over an array or a collection, as it provides a convenient way to control the iteration using an index or an iterator.
9. Which type of loop is best known for its boolean condition that controls entry to the loop?
Answer:
Explanation:
A while loop has a condition that returns a boolean that controls the loop.
10. Which type of loop is best known for using an index or counter?
Answer:
Explanation:
A traditional for loop is best known for having a loop variable counting up or down as the loop progresses. Therefore, Option B is correct.
11. Which of the following can loop through an array without referring to the elements by index?
Answer:
Explanation:
While a traditional for loop often loop through an array, it uses an index to do so, making Option B incorrect.The for-each loop goes through each element, storing it in a variable. Option C is correct.
12. If you want to skip to the next iteration without exiting the loop, which keyword would you use?
Answer:
Explanation:
The continue statement skips the current iteration and jumps to the next one.
13. In an enhanced for loop, is it possible to modify the current element?
Answer:
Explanation:
The enhanced for loop provides a read-only view, making element modification directly not possible.
14. Can a loop be nested inside another loop in Java?
Answer:
Explanation:
Java supports the nesting of any loop within another, facilitating complex iteration patterns.