for
JavaScript · Unit 3: Loops
- Full plan
- JavaScript
- 10 exercises
for repeats a block. Its three parts go inside the parentheses, separated by ;: where it starts, how long it keeps going and how it moves.
i++ adds 1 to i at the end of each round. What repeats is whatever is inside the {}.
for (let i = 0; i < 3; i++) {
console.log("Hello");
}Prints
Hello Hello Hello
The rest of the explanation is in the lesson, which is part of the full plan.
Exercises in this lesson
You do them in the app, which checks them on the spot and explains why.
1. Predict the output
What does this code print?
2. Predict the output
What does this code print?
3. Multiple choice
How many times does the block of
for (let i = 0; i < 5; i++)repeat?4. Complete the code
Complete this to print the numbers from 1 to 10.
5. Predict the output
What does this code print?
6. Predict the output
What does this code print?
7. Complete the code
Complete the countdown so it prints 5, 4, 3, 2, 1 and lifts off.
8. Find the bug
This program should print the whole 7 times table: 7, 14, 21 and on up to 70. Which line has the error?
9. Put the lines in order
Put the lines in order to print the even numbers from 1 to 6.
10. Multiple choice
What does this code do?
It opens in your browser. This lesson is part of the full plan; the first unit of each course is free.