Why loops are needed in Java - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to print numbers from 1 to 5 using a loop.

Java

for(int i = 1; i <= [1]; i++) {
    System.out.println(i);
}

Drag options to blanks, or click blank then click option'

A10

B1

C5

D0

Attempts:

3 left

💡 Hint

Common Mistakes

Using 10 instead of 5 makes the loop run too many times.

Using 0 will not print any numbers because i starts at 1.

The loop should run from 1 to 5, so the condition uses 5.

2fill in blank

medium

Complete the code to sum numbers from 1 to 4 using a loop.

Java

int sum = 0;
for(int i = 1; i <= [1]; i++) {
    sum += i;
}
System.out.println(sum);

Drag options to blanks, or click blank then click option'

A4

B3

C5

D6

Attempts:

3 left

💡 Hint

Common Mistakes

Using 5 will add an extra number.

Using 3 will miss the number 4.

The loop should add numbers from 1 to 4, so the condition uses 4.

3fill in blank

hard

Fix the error in the loop condition to print numbers from 0 to 3.

Java

for(int i = 0; i [1] 3; i++) {
    System.out.println(i);
}

Drag options to blanks, or click blank then click option'

A>

B<

C==

D<=

Attempts:

3 left

💡 Hint

Common Mistakes

Using < will stop before printing 3.

Using == will only run once when i is 3.

The loop should include 3, so use <= to include it.

4fill in blank

hard

Fill both blanks to create a loop that prints even numbers from 2 to 6.

Java

for(int i = [1]; i [2] 6; i += 2) {
    System.out.println(i);
}

Drag options to blanks, or click blank then click option'

A2

B<=

C<

D1

Attempts:

3 left

💡 Hint

Common Mistakes

Starting at 1 will print odd numbers.

Using < will miss printing 6.

The loop starts at 2 and runs while i is less than or equal to 6 to include 6.

5fill in blank

hard

Fill all three blanks to create a loop that prints numbers from 5 down to 1.

Java

for(int i = [1]; i [2] 1; i [3]) {
    System.out.println(i);
}

Drag options to blanks, or click blank then click option'

A5

B>=

C--

D++

Attempts:

3 left

💡 Hint

Common Mistakes

Using ++ will increase i and cause an infinite loop.

Using <= will never run because 5 is not less than or equal to 1.

The loop starts at 5, runs while i is greater than or equal to 1, and decreases i by 1 each time.