While loop execution flow in Java - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of a simple while loop

What is the output of the following Java code?

Java

int i = 1;
while (i <= 3) {
    System.out.print(i + " ");
    i++;
}

A 1 2

B 1 2 3 4

C 0 1 2 3

D 1 2 3

💡 Hint

Remember the loop runs while the condition is true and increments i each time.

The loop starts with i=1 and runs while i is less than or equal to 3. It prints i and then increments it. So it prints 1, 2, and 3 with spaces.

❓ Predict Output

intermediate

While loop with break statement

What will be printed by this Java code?

Java

int i = 0;
while (i < 5) {
    if (i == 3) {
        break;
    }
    System.out.print(i + " ");
    i++;
}

A 0 1 2

B 0 1 2 3

C 1 2 3

D 0 1 2 3 4

💡 Hint

The break stops the loop when i equals 3.

The loop prints i starting from 0. When i reaches 3, the break stops the loop before printing 3. So output is 0 1 2

❓ Predict Output

advanced

While loop with continue statement

What is the output of this Java code snippet?

Java

int i = 0;
while (i < 5) {
    i++;
    if (i == 3) {
        continue;
    }
    System.out.print(i + " ");
}

A 1 2 3 4 5

B 0 1 2 4 5

C 1 2 4 5

D 1 2 3 5

💡 Hint

The continue skips printing when i is 3.

The loop increments i first. When i is 3, continue skips the print statement. So it prints 1, 2, 4, 5 with spaces.

🧠 Conceptual

advanced

Understanding while loop condition evaluation

Consider this code: int i = 5; while (i > 0) { System.out.print(i + " "); i -= 2; } How many times does the loop run?

A 2 times

B 3 times

C 4 times

D 5 times

💡 Hint

Count how i changes each loop and when the condition fails.

i starts at 5, then becomes 3, then 1, then -1 which stops the loop. So it runs 3 times.

❓ Predict Output

expert

While loop with nested conditions and variable changes

What is the output of this Java code?

Java

int i = 1;
int sum = 0;
while (i <= 5) {
    if (i % 2 == 0) {
        i++;
        continue;
    }
    sum += i;
    i++;
}
System.out.println(sum);

A 9

B 15

C 6

D 10

💡 Hint

Only odd numbers are added to sum because even numbers skip the addition.

The loop adds 1, 3, and 5 to sum. Even numbers 2 and 4 are skipped. So sum = 1+3+5 = 9.