AP Computer Science Midterm Review

What will be produced by the following statement?

• I
• II
• III
• none of these

Expressions follow order of operations rules. What value will result hold after this statement is executed?

• -5
• 0
• 13
• 12

Suppose that addition and subtraction had higher precedence than multiplication and division. What would the following expression evaluate as?
(hint: Use parentheses to elevate the rank of addition and subtraction operations)

• 7
• 8
• 0
• 1

Assume aNum is a variable of type double that is positive. A program contains the boolean expression (Math.pow( aNum, 0.5 ) == Math.sqrt ( aNum )). Even though aNum^1/2 is mathematically equivalent to √aNum the above expression returns the value false in a student's program. Which of the following is the most likely reason?

• Math.pow returns an int, while Math.sqrt returns a double.
• aNum was imprecisely calculated in a previous program statement.
• The computer stores floating-point numbers with 32-bit words.
• There is round-off error in calculating the pow and sqrt functions.

If a is of type int and has a value of 0 when the segment is executed, what will happen?

• An ArithmeticException will be thrown.
• statement2, but not statement1, will be executed.
  
• statement1, but not statement2, will be executed.
  
• A syntax error will occur.

What will the output be for the following poorly formatted program segment, if the input value for x is 33?

• 33
• 3
• 3 is negative
• 33 is negative

Which of the following will evaluate to true only if boolean expressions X, Y, and Z are all false?

• !X && !( Y && !Z )
• !X || !Y || !Z
• !( X || Y || Z )
• !X || !( Y || !Z )

Assume x and y are both integers. Using the example expression, which of the following will always evaluate to true?

• x > y and y > 0
• x > y
• x < y
• x > y and y < 0

Assume that x, y, and z are all integers. In the example expression, which of the following will guarantee that the expression is true?

• z < x is false
• z < x is true
• x < y is false
• z == x * y is true

Assume x, y, and z are all integers. What will happen if x == y is false?

• /* statement 1 */ will be executed
• /* statement 2 */ will be executed
• Either /* statement 1 */ or /* statement 2 */ will be executed
• A compile-time error will occur