Why loop control is required in Java - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

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

Java

for(int i = 1; i [1] 5; 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 '>' or '>=' will not start the loop correctly.

Using '==' will only run the loop when i equals 5, missing other numbers.

The loop should continue as long as i is less than or equal to 5 to print numbers 1 through 5.

2fill in blank

medium

Complete the code to stop the loop when the number 3 is reached.

Java

for(int i = 1; i <= 5; i++) {
    if(i [1] 3) {
        break;
    }
    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 '<' or '>' will break the loop too early or too late.

Using '!=' will break the loop for all values except 3.

The loop should break when i equals 3, so the condition uses '=='.

3fill in blank

hard

Fix the error in the while loop condition to avoid an infinite loop.

Java

int count = 0;
while(count [1] 5) {
    System.out.println(count);
    count++;
}

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

A<

B>=

C==

D>

Attempts:

3 left

💡 Hint

Common Mistakes

Using '>' or '>=' causes the loop to never run or run infinitely.

Using '==' runs the loop only when count equals 5, which is never true initially.

The loop should run while count is less than 5 to avoid infinite looping.

4fill in blank

hard

Fill both blanks to create a loop that prints even numbers from 2 to 10.

Java

for(int i = [1]; i [2] 10; 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 exclude 10 from the output.

The loop starts at 2 and continues while i is less than or equal to 10 to print even numbers.

5fill in blank

hard

Fill all three blanks to create a loop that prints numbers from 10 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'

A10

B>=

C--

D++

Attempts:

3 left

💡 Hint

Common Mistakes

Using '++' will cause an infinite loop counting up.

Using '<=' will never run the loop since 10 is not less than or equal to 1.

The loop starts at 10, continues while i is greater than or equal to 1, and decreases i by 1 each time.

Practice

1.

Why do we need loop control statements like break and continue in Java loops?

easy

A. To create new variables inside loops

B. To make loops run forever without stopping

C. To manage when loops stop or skip steps

D. To print output inside loops

Solution

1. Step 1: Understand loop control purpose

   Loop control statements help decide when to stop or skip parts of a loop.

2. Step 2: Identify correct usage

   break stops the loop early, continue skips current step and moves on.

3. Final Answer:

   To manage when loops stop or skip steps -> Option C

4. Quick Check:

   Loop control = manage loop flow [OK]

Hint: Loop control changes loop flow by stopping or skipping steps [OK]

Common Mistakes:

• Thinking loop control creates variables
• Believing loops run forever without control
• Confusing printing with loop control

2.

Which of the following is the correct syntax to stop a loop immediately in Java?

for(int i = 0; i < 5; i++) {
    // stop loop here
}

easy

A. stop;

B. continue;

C. exit;

D. break;

Solution

1. Step 1: Recall Java loop control keywords

   Java uses break; to stop loops immediately.

2. Step 2: Check other options

   stop; and exit; are invalid; continue; skips current iteration but does not stop loop.

3. Final Answer:

   break; -> Option D

4. Quick Check:

   Stop loop = break [OK]

Hint: Use break to exit loops immediately [OK]

Common Mistakes:

• Using continue to stop loop
• Writing stop or exit which are invalid
• Missing semicolon after break

3.

What will be the output of this Java code?

for(int i = 1; i <= 5; i++) {
    if(i == 3) {
        continue;
    }
    System.out.print(i + " ");
}

medium

A. 1 2 3 4 5

B. 1 2 4 5

C. 3 4 5

D. 1 2

Solution

1. Step 1: Understand loop and continue effect

   The loop runs from 1 to 5. When i is 3, continue skips printing 3.

2. Step 2: Trace output values

   Prints 1, 2, skips 3, then prints 4 and 5.

3. Final Answer:

   1 2 4 5 -> Option B

4. Quick Check:

   Continue skips 3, output excludes 3 [OK]

Hint: Continue skips current step, so 3 is missing [OK]

Common Mistakes:

• Thinking continue stops the loop
• Including 3 in output
• Confusing continue with break

4.

Find the error in this Java loop code that tries to stop when i equals 4:

for(int i = 1; i <= 5; i++) {
    if(i = 4) {
        break;
    }
    System.out.print(i + " ");
}

medium

A. Using assignment (=) instead of comparison (==) in if condition

B. Missing semicolon after break

C. Loop condition should be i < 4

D. System.out.print should be System.out.println

Solution

1. Step 1: Check if condition syntax

   The condition uses i = 4 which assigns 4 to i, not compares.

2. Step 2: Correct comparison operator

   It should be i == 4 to compare values.

3. Final Answer:

   Using assignment (=) instead of comparison (==) in if condition -> Option A

4. Quick Check:

   Use == for comparison, not = [OK]

Hint: Use == to compare, = is assignment [OK]

Common Mistakes:

• Confusing = and ==
• Thinking break needs semicolon fix
• Changing loop condition unnecessarily

5.

You want to print numbers from 1 to 10 but skip multiples of 3 and stop completely if number is greater than 8. Which loop control statements should you use?

hard

A. Use continue to skip multiples of 3 and break to stop if number > 8

B. Use break to skip multiples of 3 and continue to stop if number > 8

C. Use only continue for both skipping and stopping

D. Use only break for both skipping and stopping

Solution

1. Step 1: Identify skipping condition

   To skip multiples of 3, use continue to skip printing those numbers.

2. Step 2: Identify stopping condition

   To stop loop when number > 8, use break to exit loop immediately.

3. Final Answer:

   Use continue to skip multiples of 3 and break to stop if number > 8 -> Option A

4. Quick Check:

   Continue skips, break stops loop [OK]

Hint: Continue skips steps, break stops loop completely [OK]

Common Mistakes:

• Swapping break and continue roles
• Using only one control for both tasks
• Not stopping loop when needed