Which control statement is best suited when the number of loop iterations is known in advance?

Question

BlackTom AI · Accepted Answer

When the number of iterations is known in advance, a for loop is the most appropriate control statement because it explicitly encodes initialization, termination, and step in a single construct.

1. Relevant knowledge points and concepts
- Loop types: for, while, do-while. All repeat a block of code, but their typical use-cases differ.
- A for loop is designed to run a fixed number of times by placing loop variable initialization, loop condition, and increment/decrement in one line.
- while and do-while are condition-driven and more suited to loops where the number of iterations is not known beforehand (they repeat until a condition changes during execution).

2. Step-by-step reasoning process
- Suppose you need to run a body exactly N times. A for loop directly expresses that: for (i = 0; i < N; i++) { body }.
- Initialization: i = 0 sets the starting point.
- Condition: i < N is checked before every iteration; when false, the loop stops.
- Update: i++ advances toward termination in a predictable way.
- This makes the for loop clear, concise, and less error-prone for fixed-count loops.

3. Example with intermediate steps
- Example: for (i = 0; i < 5; i++) { print(i); }
  - Iteration 1: i=0, condition 0<5 true → execute body → i becomes 1.
  - Iteration 2: i=1, condition 1<5 true → execute body → i becomes 2.
  - Iteration 3: i=2, condition 2<5 true → execute body → i becomes 3.
  - Iteration 4: i=3, condition 3<5 true → execute body → i becomes 4.
  - Iteration 5: i=4, condition 4<5 true → execute body → i becomes 5.
  - Next check: i=5, 5<5 false → loop ends. Total iterations = 5.

4. Why the correct answer is correct
- The for loop explicitly captures the iteration count in its header and reduces the chance of off-by-one or update-location errors. It is optimized semantically and syntactically for known iteration counts.

5. Why other options are less suitable
- while: checks condition before each iteration but separates initialization and update, making fixed-count loops less compact and potentially more error-prone.
- do-while: guarantees at least one execution; used when you must run the body at least once regardless of condition, not ideal when you simply need a known number of repeats.

6. Conclusion
- Therefore, the best-suited control statement when the number of loop iterations is known in advance is: for. This matches the provided answer.

Which control statement is best suited when the number of loop iterations is known in advance?单项选择题

类似问题

How many times is the following loop executed: for (int i = 0; i < 10; i = i + 2) {}

Show the output produced by the following segments of code. Assume that all variables are declared as int. w = -1; for (h = -1; h <= 4; h+=2) w = w + h; cout << w;

The type of control structure shown is best described as a

What is the output of the following code? for (int x = 1; x <= 10; x++) { x += 3; System.out.print(x + " "); }

How many times will this loop iterate? for (i = 2; i < 10; i += 4) { ... }

Question textFill in the blanks in order to write code that finds the sum of all the numbers from 5 up to and including 10. (Do not include any spaces). sum = 0for i in range(Answer 1 Question 9[input] , Answer 2 Question 9[input]): sum = sum + Answer 3 Question 9[input]

How do you initialize a 'for' loop to count from 10 down to 1?

What will be displayed after the following code is executed assuming num was initially set to zero? for n in range(0, 20, 5): num += n print(num)

更多留学生实用工具

智能学习助手

风格化写作助手

论文查重助手

文献引用助手

课堂转译助手

课堂笔记助手

Quiz搜索助手

学校历年真题

智能刷题助手

智能匹配练习

希望你的学习变得更简单