For loop in C++ - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a for loop in C++?

A for loop is a control structure that repeats a block of code a set number of times. It has three parts: initialization, condition, and update.

beginner

Write the basic syntax of a for loop in C++.

for (initialization; condition; update) {<br> // code to repeat<br>}

beginner

What happens if the condition in a for loop is false at the start?

The loop body does not run at all, and the program continues after the loop.

beginner

How can you use a for loop to print numbers from 1 to 5?

for (int i = 1; i <= 5; i++) {<br> std::cout << i << std::endl;<br>}

beginner

What is the role of the update expression in a for loop?

The update expression changes the loop variable each time the loop runs, usually to move toward the loop ending condition.

Which part of the for loop runs first?

A Initialization

B Condition check

C Update expression

D Loop body

The initialization runs first to set up the loop variable before checking the condition.

What happens if the condition in a for loop is always true?

A The loop runs once

B The loop runs forever unless broken

C The loop never runs

D The program crashes

If the condition never becomes false, the loop repeats endlessly until a break or exit.

Which symbol is used to separate the parts of a for loop?

A ;

B ,

C :

D .

Semicolons separate initialization, condition, and update in a for loop.

How do you increase the loop variable by 1 each time?

A i = i - 1

B i--

C i++

D i = 0

The i++ expression adds 1 to i each time the loop runs.

What will this loop print? for(int i=0; i<3; i++) { std::cout << i; }

A 321

B 123

C 000

D 012

The loop prints 0, then 1, then 2, all together as 012.

Explain how a for loop works in C++ and describe its three main parts.

Think about how the loop starts, checks if it should continue, runs code, and then changes the variable.

Write a for loop that counts down from 5 to 1 and prints each number.

Start with i = 5, stop when i is less than 1, and decrease i each time.