A common AP CSA mistake is forgetting how Java evaluates expressions, especially when integer division, operator precedence, remainder, and String concatenation appear together.
In this interactive practice set, we cover AP CSA Unit 1.3: Expressions and Output. These 15 multiple-choice questions target integer division, remainder operations, operator precedence, numeric expressions, and String concatenation.
Key Concepts to Remember Before You Start:
-
Integer Division:
When two integers are divided, Java performs integer division and discards
the fractional part. For example,
11 / 4evaluates to2, not2.75. -
Remainder (
%): The remainder operator returns the remainder after integer division. For example,23 % 6evaluates to5. -
Operator Precedence:
Multiplication (
*), division (/), and modulo (%) have higher precedence than addition and subtraction. Operators with the same precedence are evaluated from left to right. -
String Concatenation:
When the
+operator is used with a String, it performs concatenation. Evaluation proceeds according to Java’s normal expression rules. For example,"Age: " + 5 + 2produces"Age: 52".
AP CSA 1.3: Expressions and Output Practice
Question 1 of 15 |
Score: 0
1. Consider the following code segment. What is printed as a result of executing the code segment?
int a = 14;
int b = 5;
System.out.println(a / b);
int b = 5;
System.out.println(a / b);
Correct Answer: CBecause both
a and b are integers, Java
performs integer division. 14 / 5 is mathematically
2.8, but the fractional part is discarded, leaving 2.
2. Consider the following expression. What is printed?
int result = 4 + 5 * 3 – 8 / 2;
System.out.println(result);
System.out.println(result);
Correct Answer: BMultiplication and division have higher precedence than addition
and subtraction.
1.
2.
3. The expression becomes
4. Evaluating left to right gives
1.
5 * 3 evaluates to 15.2.
8 / 2 evaluates to 4.3. The expression becomes
4 + 15 - 4.4. Evaluating left to right gives
19 - 4 = 15.
3. What is the output of the following code segment?
System.out.println(23 % 6);
Correct Answer: DThe remainder operator (
%) returns the remainder.
6 goes into 23 three times, giving
18. The remainder is 23 - 18 = 5.
4. Consider the following code segment. What is printed?
int x = 4;
int y = 10;
System.out.println(x % y);
int y = 10;
System.out.println(x % y);
Correct Answer: BWhen calculating
4 % 10, 10 goes into 4 zero times.
Therefore, the remainder is the original value, 4.
5. Consider the following expression. What is printed?
System.out.println(12 / 3 * 2);
Correct Answer: CMultiplication and division have the same precedence, so they are
evaluated from left to right.
First,
First,
12 / 3 evaluates to 4.
Then 4 * 2 evaluates to 8.
6. What is the output of the following code segment?
System.out.println(17 % 5);
Correct Answer: CThe remainder operator (
%) returns the remainder
after integer division. 5 goes into 17
three times, giving 15. The remainder is
17 - 15 = 2.
7. Consider the following code segment. What is printed?
int val = 20 – (3 + 2) * 4 / 2;
System.out.println(val);
System.out.println(val);
Correct Answer: AParentheses evaluate first:
The expression becomes
(3 + 2) becomes 5.The expression becomes
20 - 5 * 4 / 2.Multiplication and division are then evaluated from left to right:
5 * 4 = 20, followed by
20 / 2 = 10.Finally, 20 - 10 = 10.
8. Consider the following code segment. What gets printed?
System.out.println("Result: " + 3 + 4);
Correct Answer: CEvaluation proceeds from left to right. Because the first operand
is a String, the first
+ performs concatenation.
The expression becomes "Result: 3", and the next
+ concatenates the 4, producing
"Result: 34".
9. Consider the following code segment. What gets printed?
System.out.println("Result: " + (3 + 4));
Correct Answer: ABecause of the parentheses around
(3 + 4),
the arithmetic addition is evaluated first, producing
7. The result is then concatenated with the String,
producing Result: 7.
10. Consider the following code segment. What gets printed?
double a = 15;
int b = 4;
System.out.println(a / b);
int b = 4;
System.out.println(a / b);
Correct Answer: BBecause
a is a double, the expression
performs floating-point division. The result of
15.0 / 4 is 3.75.
11. Consider the following expression. What gets printed?
int result = 5 + 2 * (10 % 4) – 3;
System.out.println(result);
System.out.println(result);
Correct Answer: C1. Parentheses first:
2. The expression becomes
3. Multiplication:
4. The expression becomes
5. Addition and subtraction are evaluated from left to right:
10 % 4 evaluates to 2.2. The expression becomes
5 + 2 * 2 - 3.3. Multiplication:
2 * 2 = 4.4. The expression becomes
5 + 4 - 3.5. Addition and subtraction are evaluated from left to right:
9 - 3 = 6.
12. Consider the following code segment. What gets printed?
System.out.println(5 + 2 + " equals 7");
Correct Answer: BEvaluation happens from left to right.
First,
First,
5 + 2 is integer addition, producing
7.The next + combines the integer 7
with the String " equals 7", producing
7 equals 7.
13. Consider the following code segment. What gets printed?
System.out.println("Answer: " + 11 / 2);
Correct Answer: CDivision has higher precedence than the String concatenation
operation here, so
11 / 2 is evaluated first.Because both operands are integers, integer division produces
5.The result is then concatenated with the String, producing
Answer: 5.
14. Which of the following expressions evaluates to
0
if and only if the positive integer variable num
is an even number?Correct Answer: BThe remainder operator returns the remainder.
When a positive integer is even, dividing it by 2 leaves a
remainder of
0.Therefore, num % 2 evaluates to 0
exactly when num is even.
15. Assume
int num = 8473;.
Which of the following expressions will correctly extract the
last digit (3) from num?Correct Answer: AUsing modulo 10 (
% 10) extracts the rightmost digit
of a positive base-10 integer.The remainder of 8473 / 10 is 3.By contrast, num / 10 using integer division removes
the last digit and produces 847.Unit 1.3 Practice Complete!
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AP CSA Practice Navigation
Why Expressions and Operator Precedence Matter for AP CSA
Expression evaluation is an important part of tracing Java code. Integer division, remainder, operator precedence, and String concatenation can change the value produced by an expression.
When tracing AP CSA code, evaluate parentheses first, then apply the appropriate operator precedence and left-to-right evaluation rules. Pay particular attention when integer and floating-point values or Strings appear in the same expression.
Continue Your AP CSA Practice
After practicing expressions and output, continue with the next available practice topic: Topic 1.5, Casting and Range of Variables. Topic 1.4 is part of the current College Board framework but does not yet have a dedicated practice page on JavaTutorOnline.