Expressions and Output() - AP Computer Science A

1. What is the result of 10 % 3 in Java?

   1. Modulus operator returns the remainder after division.

2. Identify the error: System.out.println('Hello' - 'World');

   Operator '-' cannot be applied to Strings. Subtraction operator is not defined for String operands.

3. What is the output of: System.out.println(4 + 2 * 3 - 1);?

   9. Order: $2 \times 3 = 6$, then $4 + 6 - 1 = 9$.

4. How is a string concatenated with an integer in Java?

   Using the + operator. The $+$ operator performs concatenation when one operand is a string.

5. What is the output of: System.out.println(8 / 3.0);?

   2.6666666666666665. Double division produces precise floating-point result.

6. What does the expression 2 * (3 + 4) evaluate to?

   14. Parentheses force addition first: $(3 + 4) = 7$, then $2 \times 7 = 14$.

7. Identify the error: System.out.println('Sum: ' + 5 + 3);

   Output is 'Sum: 53', not 'Sum: 8'. String concatenation with $+$ operator evaluates left-to-right without parentheses.

8. How do you declare a constant in Java?

   Using the final keyword. Makes variables immutable after initialization.

9. What is the result of: System.out.println(4 * 0.5);?

   2.0. Integer multiplied by double results in double type.

10. What is the output of: System.out.println(9 / 2.0);?

    4.5. Double divisor produces floating-point division result.

11. What is the operator used for modulus in Java?

    %. Returns the remainder of integer division.

12. What is the result of: System.out.println(6.0 / 3);?

    2.0. Double dividend produces floating-point division.

13. What is the result of: System.out.println('a' + 1);?

    98. Character 'a' has ASCII value 97, so $97 + 1 = 98$.

14. What is the output of: System.out.println('A' + 'B');?

    131. ASCII values: A=65, B=66, so $65 + 66 = 131$.

15. What is the result of: System.out.println(7 - 3 * 2);?

    1. Multiplication has higher precedence: $3 \times 2 = 6$, then $7 - 6 = 1$.

16. What does System.out.print() do differently than println()?

    Output without a newline. Does not add a newline character after output.

17. What is the output of: System.out.println(3.0 / 2);?

    1.5. Double division produces a floating-point result.

18. What is the result of: System.out.println(12 / 5);?

    2. Integer division truncates the decimal portion.

19. What will be printed: System.out.println('2' + 3 + 4);?

    234. Character '2' concatenates, then numeric addition occurs.

20. What does the expression 2 + 3 * 4 evaluate to?

    14. Multiplication precedence: $3 \times 4 = 12$, then $2 + 12 = 14$.

21. What is the output of: System.out.println('A' + 1);?

    66. Character 'A' has ASCII value 65, so $65 + 1 = 66$.

22. What is the value of a boolean expression: 5 > 3 && 3 > 5?

    false. Second condition is false, making the entire AND expression false.

23. What is the output of: System.out.println(5 + 2 * 3);?

    11. Multiplication precedence: $2 \times 3 = 6$, then $5 + 6 = 11$.

24. What will be printed: System.out.println(true && false);?

    false. Logical AND requires both operands to be true.

25. What is the output of: System.out.println(0.1 + 0.2 == 0.3);?

    false. Floating-point arithmetic precision issues cause inequality.

26. What is the result of: System.out.println('Java' + 1 + 2);?

    Java12. String concatenation evaluates left-to-right without grouping.

27. What is the result of: System.out.println(10 % 2);?

    0. 10 divided by 2 has no remainder.

28. What does the '==' operator compare in Java?

    Primitive values or object references. Compares actual values for primitives, memory addresses for objects.

29. What is the output of: System.out.println('Java' + (1 + 2));?

    Java3. Parentheses force addition first, then concatenation.

30. What is the result of: System.out.println(10 / 3);?

    3. Integer division truncates the decimal portion in Java.

31. How do you print a double quote in a string in Java?

    Using escape sequence \". Backslash escapes special characters in string literals.

32. What is the operator precedence of *, /, %, +, - in Java?

    *, /, % have higher precedence than +, -. Multiplication, division, and modulus are evaluated before addition and subtraction.

33. What will be printed: System.out.println('a' + 'b');?

    195. ASCII values: a=97, b=98, so $97 + 98 = 195$.

34. What does the expression 5 + 3 * 2 evaluate to in Java?

    11. Multiplication has higher precedence than addition: $3 \times 2 = 6$, then $5 + 6 = 11$.

35. Which data type can store a single character in Java?

    char. Stores a single Unicode character in 16 bits.

Study these flashcards