AP Computer Science A Unit 2 Exam (2025) - Selection & Iteration

Prerequisite: Before attempting this exam, make sure you have mastered AP Computer Science A Unit 1 - Objects, Methods & Expressions , as Unit 2 builds directly on those concepts.

Looking for written practice? SKIP TO: AP CSA Unit 2 Free-Response Practice (FRQs) to strengthen your loop and conditional reasoning.

This AP Computer Science A Unit 2 exam is designed for the new 2025 AP CSA 4-Unit curriculum and focuses on decision-making and repetition, two of the most heavily tested skills on the AP exam.

Unit 2 builds on foundational Java syntax by teaching programs how to make decisions using boolean expressions and repeat actions using loops. These skills appear extensively in both multiple-choice questions and free-response questions.

This assessment includes high-difficulty multiple-choice questions modeled after:

✔ The official AP Computer Science A Course and Exam Description (CED)
✔ Barron's AP CSA loop-tracing and logic challenges
✔ CodeHS and AP Classroom progress-check style problems
✔ Common AP CSA mistakes involving conditionals, short-circuit logic, and loop errors

The questions emphasize precise tracing, boolean reasoning, and the ability to recognize loop patterns and pitfalls under exam pressure.

Unit 2 Topics Covered:

Boolean expressions and logical operators (&&, ||, !)
Relational operators and compound conditions
if, else-if, else, and nested conditionals
Short-circuit evaluation
while loops and for loops
Common loop patterns (counting, summing, searching)
Off-by-one errors and infinite loops
Tracing and debugging selection + iteration logic

At the bottom of this exam, you will complete two concise Free-Response Questions (FRQs) written in the style of AP Classroom Progress Checks, where you will write and test code using a Java sandbox.

Exam Tip: Many Unit 2 errors on the AP exam come from mis-grouped boolean expressions, incorrect loop boundaries, and misunderstanding short-circuit evaluation. Trace carefully.

Time Left: 45:00

AP Computer Science A - Unit 2 Exam

Selection & Iteration (High Difficulty)

Section I: Multiple Choice (30 Questions)

Question 1

What is printed?

int x = 0;
if (x != 0 && 10 / x > 1)
    System.out.println("Yes");
else
    System.out.println("No");

A. Yes B. No C. Runtime error D. Nothing

Answer: B
Short-circuit evaluation prevents division by zero.

Question 2

How many times does the loop execute?

for (int i = 2; i <= 20; i += 3)
    System.out.print(i + " ");

A. 5 B. 6 C. 7 D. 8

Answer: B
2,5,8,11,14,17 → 6 iterations.

Question 3

Which condition checks if x is outside 1-10 inclusive?

A. x < 1 || x > 10 B. x <= 1 && x >= 10 C. !(x > 1 && x < 10) D. x < 1 && x > 10

Answer: A
Outside a range requires OR.

Question 4

What is printed?

int n = 5;
while (n > 0) {
    n -= 2;
    System.out.print(n + " ");
}

A. 3 1 -1 B. 5 3 1 C. 3 1 D. Infinite loop

Answer: A
Loop stops when n becomes negative.

Question 5

What is printed?

String s = "java";
for (int i = 0; i < s.length(); i++)
    if (s.charAt(i) == 'a')
        System.out.print(i + " ");

A. 0 2 B. 1 3 C. 2 4 D. 1 2

Answer: B
'a' appears at indices 1 and 3.

Question 6

Which statement about loops is TRUE?

A. while loops always run once B. for loops cannot be infinite C. Loop conditions must eventually become false D. Loops cannot contain if statements

Answer: C
All correct loops must terminate.

Question 7

What is printed?

int x = 10;
if (x > 5)
    if (x < 8)
        System.out.println("A");
    else
        System.out.println("B");

A. A B. B C. Nothing D. Compile error

Answer: B
Else pairs with the nearest if.

Question 8

What is printed?

int sum = 0;
for (int i = 1; i <= 4; i++)
    sum += i;
System.out.println(sum);

A. 6 B. 10 C. 12 D. 16

Answer: B
1+2+3+4 = 10.

Question 9

Which expression generates a random integer from 1-6 inclusive?

A. (int)(Math.random() * 6) B. (int)(Math.random() * 6) + 1 C. (int)(Math.random() * 5) + 1 D. (int)(Math.random() * 7)

Answer: B
Correct inclusive random pattern.

Question 10

What is printed?

String s = "hello";
s.toUpperCase();
System.out.println(s);

A. hello B. HELLO C. Hello D. Runtime error

Answer: A
Strings are immutable.

Question 11

What is printed?

int x = 1;
while (x < 10) {
    x *= 2;
}
System.out.println(x);

A. 8 B. 10 C. 16 D. Infinite loop

Answer: C
1 → 2 → 4 → 8 → 16, then condition fails.

Question 12

Which expression is equivalent to !(a >= 5 && a <= 10)?

A. a < 5 || a > 10 B. a < 5 && a > 10 C. !(a > 5 || a < 10) D. a == 5 || a == 10

Answer: A
De Morgan's Law: NOT (AND) → OR of negations.

Question 13

What is printed?

int count = 0;
for (int i = 1; i <= 10; i++) {
    if (i % 4 == 0)
        count++;
}
System.out.println(count);

A. 2 B. 3 C. 4 D. 5

Answer: A
Only 4 and 8 are divisible by 4.

Question 14

What is printed?

int x = 3;
for (int i = 0; i < x; i++) {
    x--;
    System.out.print(i + " ");
}

A. 0 B. 0 1 C. 0 1 2 D. Infinite loop

Answer: A
x decreases, causing early termination.

Question 15

Which statement about while loops is TRUE?

A. They always execute once B. Condition checked after loop C. They may execute zero times D. They cannot be infinite

Answer: C
If the condition starts false, the loop never runs.

Question 16

What is printed?

String s = "APCSA";
for (int i = 1; i < s.length(); i += 2)
    System.out.print(s.charAt(i));

A. PSA B. ASA C. PCA D. APS

Answer: A
Indices 1,3,5 → P, S, A.

Question 17

What causes an infinite loop?

A. Variable moves toward condition B. Condition becomes false C. Loop variable never changes D. Using a for loop

Answer: C
If nothing changes, the condition never becomes false.

Question 18

What is printed?

int x = 10;
if (x < 5 || x / 2 > 3)
    System.out.println("A");
else
    System.out.println("B");

A. A B. B C. Runtime error D. Nothing

Answer: A
10 / 2 = 5, which is greater than 3.

Question 19

What is printed?

int n = 7;
int count = 0;
while (n > 0) {
    n -= 3;
    count++;
}
System.out.println(count);

A. 2 B. 3 C. 4 D. 5

Answer: B
7 → 4 → 1 → -2 → 3 iterations.

Question 20

Which condition checks if x equals 2, 4, or 6?

A. x == 2 || 4 || 6 B. x == 2 && x == 4 && x == 6 C. x == 2 || x == 4 || x == 6 D. x >= 2 && x <= 6

Answer: C
Each equality must be explicitly stated.

Question 21

What is printed?

for (int i = 5; i > 0; i--) {
    if (i == 3)
        break;
    System.out.print(i + " ");
}

A. 5 4 3 B. 5 4 C. 4 3 D. 5 4 2

Answer: B
Loop stops when i equals 3.

Question 22

Which best describes short-circuit evaluation?

A. Both sides always evaluate B. Second condition may be skipped C. Conditions evaluate randomly D. Only applies to OR

Answer: B
Evaluation stops once result is known.

Question 23

What is printed?

int sum = 0;
for (int i = 1; i <= 3; i++)
    for (int j = 1; j <= 2; j++)
        sum++;
System.out.println(sum);

A. 5 B. 6 C. 7 D. 8

Answer: B
3 x 2 = 6 total iterations.

Question 24

What is printed?

int x = 1;
while (x <= 5) {
    System.out.print(x + " ");
    x += 2;
}

A. 1 3 5 B. 1 2 3 4 5 C. 2 4 D. Infinite loop

Answer: A
x increases by 2 each time.

Question 25

Which loop counts from 10 down to 1?

A. for (int i = 1; i <= 10; i--) B. for (int i = 10; i >= 1; i--) C. for (int i = 10; i <= 1; i--) D. for (int i = 1; i >= 10; i++)

Answer: B
Starts at 10 and decrements to 1.

Question 26

What is printed?

int x = 4;
int y = 0;
while (x > 0) {
    y++;
    x /= 2;
}
System.out.println(y);

A. 2 B. 3 C. 4 D. Infinite loop

Answer: B
4 → 2 → 1 → 0 → 3 iterations.

Question 27

Which statement about break is TRUE?

A. Exits only an if-statement B. Exits the nearest loop C. Skips the loop condition D. Ends the program

Answer: B
break exits the innermost loop immediately.

Question 28

What is printed?

int count = 0;
for (int i = 1; i <= 20; i++) {
    if (i % 2 == 0 && i % 5 == 0)
        count++;
}
System.out.println(count);

A. 1 B. 2 C. 3 D. 4

Answer: B
10 and 20 satisfy both conditions.

Question 29

What is printed?

int i = 0;
while (i < 5)
    System.out.print(i++);

A. 01234 B. 12345 C. 012345 D. Infinite loop

Answer: A
Post-increment prints before incrementing.

Question 30

Which scenario BEST uses a sentinel-controlled loop?

A. Looping a fixed number of times B. Reading input until -1 is entered C. Printing numbers 1-100 D. Traversing a String

Answer: B
Sentinel loops terminate on a specific value.

Š Test Summary

Section II: Free Response (Progress Check Style)

FRQ 1 - Loop Logic

Write a method countMultiples that returns how many integers between start and end inclusive are divisible by k.

public static int countMultiples(int start, int end, int k)

FRQ 2 - String Traversal

Write a method hasAlternatingCase that returns true if a string alternates uppercase and lowercase letters starting at index 0.

public static boolean hasAlternatingCase(String s)

Next Step: Unit 3

Once you are comfortable with selection and iteration, you are ready to move on to

AP Computer Science A Unit 3 - Class Creation

, where you will design classes, write constructors, and define methods.

Want to test everything together? Try our >

Full AP CSA Practice Exam

for a timed, exam-length experience.

Stuck on loops or conditionals? Explore

AP CSA tutoring for loops and conditionals

with step-by-step guidance.

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