Unit 2 Practice Exam: Selection and Iteration | AP CSA

AP CSA Practice Exam

Unit 2 Practice Exam: Selection and Iteration

50 Questions • 2025-2026 Curriculum • Unit 2: Boolean Expressions, if/else, for and while Loops (25-35% of exam)

0Correct

0Incorrect

0/50Progress

Exam Overview: Unit 2 covers 25-35% of the AP CSA exam — the single largest unit weight. The full AP CSA exam is 42 MCQ (55%) plus 4 FRQ (45%), delivered fully digitally via Bluebook on May 15, 2026 (afternoon session). Topics in this set: boolean expressions, short-circuit evaluation, if / if-else / if-else-if, for and while loops, and nested iteration. Formats: Error Detection, I/II/III multi-select, and Predict the Output — all at AP exam difficulty.

Section 1: Boolean Expressions and Comparisons

Predict the Output

Question 1

Before looking at the choices, trace the code and predict the output.

int p = 5;
int q = 10;
boolean r = (p > 3) && (q < 8);
System.out.println(r);

A. true B. false C. 1 D. A compile-time error occurs

I/II/III Format

Question 2

Consider the following declarations:

int m = 7;
int n = 4;

Which of the following expressions evaluate to true?

I. (m > n) || (m == n)
II. !(m < n) && (n < 10)
III. (m + n == 11) && (m - n == 2)

A. I only B. II and III only C. I and II only D. I, II, and III

Error Detection

Question 3

A student wants to check whether a value is between 1 and 10 inclusive. Which expression is WRITTEN INCORRECTLY?

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

Predict the Output

Question 4

Before looking at the choices, predict the output.

String w1 = new String("Code");
String w2 = new String("Code");
System.out.println(w1 == w2);
System.out.println(w1.equals(w2));

A. true then true B. true then false C. false then false D. false then true

Error Detection

Question 5

Consider the following code segment. Will it run without exceptions, and why?

int numer = 10;
int denom = 0;
if (denom != 0 && numer / denom > 2) {
    System.out.println("Big");
} else {
    System.out.println("Small or zero");
}

A. No -- an ArithmeticException (divide by zero) is thrown at runtime B. No -- the code has a compile-time error C. Yes -- short-circuit evaluation prevents the division from executing when the first condition is false D. Yes -- Java quietly returns zero for any divide-by-zero with integers

I/II/III Format

Question 6

Which of the following expressions are equivalent to !(a && b) by De Morgan's Law?

I. !a && !b
II. !a || !b
III. (!a) || (!b)

A. I only B. II and III only C. II only D. I, II, and III

Predict the Output

Question 7

Before looking at the choices, predict the output.

int j = 15;
boolean t = (j > 10) == (j < 20);
System.out.println(t);

A. true B. false C. 15 D. A compile-time error occurs

Error Detection

Question 8

A student writes the following code intending to print Match when two Strings are equal. Will it work as intended?

String first = "yes";
String second = "Yes";
if (first == second) {
    System.out.println("Match");
} else if (first.equals(second)) {
    System.out.println("Case-match");
} else if (first.equalsIgnoreCase(second)) {
    System.out.println("Ignore-case match");
} else {
    System.out.println("No match");
}

A. It prints Match because both Strings have the value yes B. It prints Case-match because equals compares content C. It prints No match D. It prints Ignore-case match because equalsIgnoreCase handles the different capitals

Predict the Output

Question 9

Before looking at the choices, predict the output. Pay attention to evaluation order.

int k = 5;
if (k < 10 || ++k > 100) {
    System.out.println(k);
}

A. 4 B. 5 C. 6 D. 100

I/II/III Format

Question 10

Which of the following conditions are TRUE when a = 6 and b = 4?

I. a % 2 == 0 && b % 2 == 0
II. (a + b) % 2 != 0
III. a > b && a - b < 5

A. I only B. II and III only C. I and III only D. I, II, and III

Section 2: if, if-else, and if-else-if Statements

Error Detection

Question 11

A student wants the code to print exactly one letter grade based on the score. Which version achieves this CORRECTLY?

A. Use an if-else-if chain starting with if (s >= 90), then else if (s >= 80), then else if (s >= 70) B. Use three separate if statements: if (s >= 90), if (s >= 80), if (s >= 70) C. Use three if statements with else only on the last one D. Use if (s >= 70) first, then else if (s >= 80), then else if (s >= 90)

Predict the Output

Question 12

Before looking at the choices, trace each branch carefully.

int s = 85;
if (s >= 90) {
    System.out.println("A");
}
if (s >= 80) {
    System.out.println("B");
}
if (s >= 70) {
    System.out.println("C");
}

A. A B. B C. A then B then C D. B then C

Error Detection

Question 13

What does the following code print?

int v = 5;
if (v > 10)
    System.out.println("X");
    System.out.println("Y");
System.out.println("Z");

A. X then Y then Z B. Y then Z C. Z only D. Nothing is printed

Predict the Output

Question 14

Before looking at the choices, trace the nested conditional.

int v = 15;
if (v > 10) {
    if (v > 20) {
        System.out.println("High");
    } else {
        System.out.println("Mid");
    }
} else {
    System.out.println("Low");
}

A. Mid B. High C. Low D. Mid then Low

I/II/III Format

Question 15

Consider the following code with int p = 10, q = 20, r = 30. Which of the following will correctly identify the LARGEST value?

I. if (p > q && p > r) largest = p; else if (q > r) largest = q; else largest = r;
II. largest = p; if (q > largest) largest = q; if (r > largest) largest = r;
III. if (p > q) largest = p; if (r > largest) largest = r;

A. I only B. II and III only C. I and II only D. I, II, and III

Predict the Output

Question 16

Before looking at the choices, predict the output.

int temp = 72;
boolean rain = false;
if (temp > 80 && !rain) {
    System.out.println("Beach");
} else if (temp > 60 || !rain) {
    System.out.println("Park");
} else {
    System.out.println("Home");
}

A. Beach B. Park C. Home D. Beach then Park

Error Detection

Question 17

A student writes the following code intending to print Positive when the value is strictly positive. What does it actually print when n = 0?

int n = 0;
if (n > 0) {
    System.out.println("Positive");
} else {
    System.out.println("Negative");
}

A. Positive B. Negative, correctly C. Nothing D. Negative, which is a logic bug because zero is neither positive nor negative

Predict the Output

Question 18

Before looking at the choices, trace the branch.

String letter = "B";
String msg;
if (letter.equals("A")) {
    msg = "Top";
} else if (letter.equals("B")) {
    msg = "Good";
} else if (letter.equals("C")) {
    msg = "Ok";
} else {
    msg = "Low";
}
System.out.println(msg);

A. Top B. Ok C. Good D. Low

Predict the Output

Question 19

Before looking at the choices, trace the leap-year logic carefully.

int yr = 2100;
boolean leap;
if (yr % 400 == 0) {
    leap = true;
} else if (yr % 100 == 0) {
    leap = false;
} else if (yr % 4 == 0) {
    leap = true;
} else {
    leap = false;
}
System.out.println(leap);

A. false B. true C. 2100 D. A compile-time error occurs

I/II/III Format

Question 20

Consider int x = 5. Which of the following code fragments print exactly YES (and nothing else)?

I. if (x > 0) System.out.println("YES");
II. if (x > 0) { System.out.println("YES"); } else { System.out.println("NO"); }
III. if (x > 0) System.out.println("YES"); System.out.println("NO");

A. I only B. I, II, and III C. II and III only D. I and II only

Section 3: for Loops

Predict the Output

Question 21

Before looking at the choices, trace the loop.

int total = 0;
for (int i = 1; i <= 5; i++) {
    total += i;
}
System.out.println(total);

A. 10 B. 15 C. 20 D. 25

Error Detection

Question 22

A student writes this loop expecting it to print the numbers 1 through 10. What is WRONG?

for (int i = 1; i < 10; i++) {
    System.out.print(i + " ");
}

A. Nothing is wrong; it prints 1 through 10 correctly B. The loop has a compile-time error because i is not declared outside C. The loop is off by one; it prints 1 through 9, missing 10 D. The loop runs forever because i is never reset

Predict the Output

Question 23

Before looking at the choices, predict the output.

int result = 1;
for (int i = 1; i <= 4; i++) {
    result *= i;
}
System.out.println(result);

A. 24 B. 10 C. 4 D. 100

I/II/III Format

Question 24

Which of the following loops print exactly 2 4 6 8 10 (separated by spaces)?

I. for (int i = 2; i <= 10; i += 2) System.out.print(i + " ");
II. for (int i = 1; i <= 5; i++) System.out.print((i * 2) + " ");
III. for (int i = 10; i >= 2; i -= 2) System.out.print(i + " ");

A. I only B. I, II, and III C. II and III only D. I and II only

Predict the Output

Question 25

Before looking at the choices, trace the loop carefully.

int count = 0;
for (int i = 0; i < 10; i += 3) {
    count++;
}
System.out.println(count);

A. 3 B. 4 C. 9 D. 10

Error Detection

Question 26

A student wants to print the digits of a number from right to left. Which code CORRECTLY prints the digits of 1234 as 4 3 2 1?

A. for (int i = 1234; i > 0; i /= 10) System.out.print(i % 10 + " "); B. for (int i = 1234; i > 0; i--) System.out.print(i % 10 + " "); C. for (int i = 0; i < 1234; i++) System.out.print(i % 10 + " "); D. for (int i = 1234; i >= 0; i /= 10) System.out.print(i % 10 + " ");

Predict the Output

Question 27

Before looking at the choices, trace the loop.

int sum = 0;
for (int i = 1; i <= 10; i++) {
    if (i % 2 == 0) {
        sum += i;
    }
}
System.out.println(sum);

A. 25 B. 45 C. 30 D. 55

I/II/III Format

Question 28

Which of the following fragments print the numbers 1 2 3 4 5 in order (each separated by a space)?

I. for (int i = 1; i <= 5; i++) System.out.print(i + " ");
II. for (int i = 0; i < 5; i++) System.out.print((i + 1) + " ");
III. for (int i = 5; i >= 1; i--) System.out.print(i + " ");

A. I only B. I and II only C. II and III only D. I, II, and III

Error Detection

Question 29

What is wrong with the following loop that intends to print 0 1 2 3 4?

for (int i = 0; i < 5; i++);
{
    System.out.print(i + " ");
}

A. Nothing is wrong; it prints 0 1 2 3 4 B. It prints nothing because i starts at zero C. It prints 0 1 2 3 4 5 (off-by-one error) D. The stray semicolon after the for header makes the loop body empty; then the block prints i, which is now out of scope (compile error)

Predict the Output

Question 30

Before looking at the choices, trace the nested loop.

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

A. 3 B. 5 C. 6 D. 9

Section 4: while Loops

Predict the Output

Question 31

Before looking at the choices, trace the while loop.

int i = 1;
int prod = 1;
while (i <= 5) {
    prod *= i;
    i++;
}
System.out.println(prod);

A. 120 B. 24 C. 15 D. 720

Error Detection

Question 32

What is the MOST LIKELY problem with the following loop?

int i = 10;
while (i > 0) {
    System.out.println(i);
}

A. Nothing is wrong; it prints 10, 9, 8, and so on down to 1 B. It prints 10 once, then the program ends C. It does not print anything because i starts greater than 0 D. It is an infinite loop because i is never decremented

I/II/III Format

Question 33

Consider the loop shown. Which of the following claims are TRUE about it?

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

I. The loop prints 0 1 2 3 4.
II. When the loop ends, i equals 5.
III. The loop body executes exactly 5 times.

A. I only B. I, II, and III C. II and III only D. I and III only

Predict the Output

Question 34

Before looking at the choices, trace the loop.

int n = 100;
int count = 0;
while (n > 1) {
    n /= 2;
    count++;
}
System.out.println(count);

A. 5 B. 7 C. 6 D. 50

Error Detection

Question 35

A student writes the following code intending to read numbers until a negative number is entered. What is wrong?

Scanner sc = new Scanner(System.in);
int num = 1;
while (num > 0);
{
    num = sc.nextInt();
    System.out.println(num);
}

A. A semicolon after the while condition creates an infinite empty loop B. Nothing is wrong C. The Scanner should be closed before the loop D. num should be declared inside the loop body

Predict the Output

Question 36

Before looking at the choices, trace the Euclidean algorithm for the GCD.

int a = 48;
int b = 18;
while (b != 0) {
    int t = b;
    b = a % b;
    a = t;
}
System.out.println(a);

A. 2 B. 48 C. 18 D. 6

I/II/III Format

Question 37

Which of the following while-loop fragments print 1 2 3 (separated by spaces)?

I. int i = 1; while (i <= 3) { System.out.print(i + " "); i++; }
II. int i = 1; while (i < 4) { System.out.print(i + " "); i++; }
III. int i = 0; while (i < 3) { i++; System.out.print(i + " "); }

A. I only B. I, II, and III C. II and III only D. I and II only

Predict the Output

Question 38

Before looking at the choices, trace the loop.

int x = 2;
int steps = 0;
while (x < 100) {
    x *= x;
    steps++;
}
System.out.println(steps);

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

Error Detection

Question 39

A student wants to find the first index where a substring of length 1 equals "a" in a String. Which version is WRITTEN CORRECTLY and is safe on all strings?

A. int i = 0; while (i < s.length() && !s.substring(i, i+1).equals("a")) { i++; } B. int i = 0; while (s.substring(i, i+1).equals("a")) { i++; } C. int i = 0; while (!s.substring(i, i+1).equals("a") && i < s.length()) { i++; } D. int i = 0; while (i <= s.length() && !s.substring(i, i+1).equals("a")) { i++; }

Predict the Output

Question 40

Before looking at the choices, trace the loop that extracts digits.

int n = 307;
int sum = 0;
while (n > 0) {
    sum += n % 10;
    n /= 10;
}
System.out.println(sum);

A. 3 B. 7 C. 307 D. 10

Section 5: Nested Loops and Iteration Algorithms

Predict the Output

Question 41

Before looking at the choices, trace the nested loop.

int t = 0;
for (int i = 1; i <= 3; i++) {
    for (int j = 1; j <= i; j++) {
        t += j;
    }
}
System.out.println(t);

A. 6 B. 10 C. 9 D. 18

Error Detection

Question 42

A student writes the following palindrome check. Will it correctly report whether the String is a palindrome?

String s = "racecar";
boolean pal = true;
for (int i = 0; i < s.length(); i++) {
    if (!s.substring(i, i+1).equals(s.substring(s.length()-1-i, s.length()-i))) {
        pal = false;
    }
}
System.out.println(pal);

A. Yes, but it is inefficient because it compares each character TWICE and should only loop through the first half B. Yes, and it is also the most efficient approach C. No, because the right-hand substring indices are computed incorrectly D. No, because palindromes cannot be checked with a for loop

I/II/III Format

Question 43

Consider nested loops that print pairs of values. Which of the following fragments would print exactly 9 lines of output?

I. for (int i = 1; i <= 3; i++) for (int j = 1; j <= 3; j++) System.out.println(i + " " + j);
II. for (int i = 0; i < 9; i++) System.out.println(i);
III. for (int i = 1; i <= 3; i++) { for (int j = 1; j <= i; j++) System.out.println(i + " " + j); }

A. I only B. I, II, and III C. II and III only D. I and II only

Predict the Output

Question 44

Before looking at the choices, trace the nested loop.

int count = 0;
for (int i = 0; i < 5; i++) {
    for (int j = 0; j < 5; j++) {
        if (i == j) {
            count++;
        }
    }
}
System.out.println(count);

A. 4 B. 10 C. 5 D. 25

Error Detection

Question 45

A student writes the following loop to count vowels in a String. What does it count INSTEAD?

String s = "programming";
int k = 0;
for (int i = 0; i < s.length(); i++) {
    String ch = s.substring(i, i+1);
    if (ch.equals("a") || ch.equals("e") || ch.equals("i") || ch.equals("o") || ch.equals("u")) {
        k = 1;
    }
}
System.out.println(k);

A. It prints the correct count of vowels B. It prints 1 if there is at least one vowel and 0 otherwise (a flag), not the count C. It prints the total length of the string D. It prints the index of the last vowel

Predict the Output

Question 46

Before looking at the choices, trace the loop that reverses a String.

String src = "ABCDE";
String rev = "";
for (int i = src.length() - 1; i >= 0; i--) {
    rev += src.substring(i, i+1);
}
System.out.println(rev);

A. EDCBA B. ABCDE C. EABCD D. ABCDEEDCBA

I/II/III Format

Question 47

Which of the following fragments correctly compute the sum of the digits of int num = 125? (Assume num is positive.)

I. int s = 0; while (num > 0) { s += num % 10; num /= 10; } // result in s
II. int s = 0; for (int i = 0; i < 3; i++) { s += num % 10; num /= 10; } // result in s
III. int s = 0; while (num >= 10) { s += num % 10; num /= 10; } s += num; // result in s

A. I only B. II and III only C. I and III only D. I, II, and III

Predict the Output

Question 48

Before looking at the choices, trace the count.

String data = "abcabc";
int c = 0;
for (int i = 0; i <= data.length() - 3; i++) {
    if (data.substring(i, i + 3).equals("abc")) {
        c++;
    }
}
System.out.println(c);

A. 1 B. 6 C. 3 D. 2

Predict the Output

Question 49

Before looking at the choices, trace the binary-search-style loop.

int target = 42;
int lo = 1;
int hi = 100;
int guesses = 0;
while (lo <= hi) {
    int mid = (lo + hi) / 2;
    guesses++;
    if (mid == target) break;
    if (mid < target) lo = mid + 1;
    else hi = mid - 1;
}
System.out.println(guesses);

A. 5 B. 7 C. 6 D. 42

I/II/III Format

Question 50

Consider the following loop. Which of the following claims are TRUE?

int p = 1;
int q = 1;
for (int i = 0; i < 5; i++) {
    for (int j = 0; j < 5; j++) {
        if (i == j) p++;
        if (i + j == 4) q++;
    }
}

I. After the loops, p equals 6.
II. After the loops, q equals 6.
III. The inner body executes exactly 25 times.

A. I only B. III only C. I, II, and III D. I and II only

← Unit 1: Objects and Methods All Unit Exams Unit 3: Class Creation →

Get in Touch

Whether you're a student, parent, or teacher — I'd love to hear from you.

Just want free AP CS resources?

Enter your email below and check the subscribe box — no message needed. Students get daily practice questions and study tips. Teachers get curriculum resources and teaching strategies.

Typically responds within 24 hours

✓

Message Sent!

Thanks for reaching out. I'll get back to you within 24 hours.

Name *

Email *

I am a... (optional)

Which course? (optional)

Phone (optional)

How did you find us? (optional)

🏫 Welcome, fellow educator!

I offer curriculum resources, practice materials, and study guides designed for AP CS teachers. Let me know what you're looking for — whether it's classroom materials, a guest speaker, or Teachers Pay Teachers resources.

Message (optional — leave blank if just subscribing)

Send me free AP CS exam tips — daily practice questions, study resources, and exam strategies. + 20% OFF TUTORING
Unsubscribe anytime.

✉

[email protected]

📚

Courses

AP CSA, CSP, & Cybersecurity

⏱

Response Time

Within 24 hours

Prefer email? Reach me directly at [email protected]