Java Basics #1

Which of the following pairs of declarations will cause an error message?

I.  double x = 14.7;
     int y = x;

II.  double x = 14.7;
      int y = (int) x;

III.  int x = 14;
       double y = x;

• None

• I only

• II only

• III only

• I and III only

What output will be produced by:

System.out.print("\\* This is not\n a comment *\\"):

• * This is not a comment *

• \* This is not a comment *\

• * This is not

  a comment *

• \\* This is not

  a comment *\\

• \* This is not

  a comment *\

Refer to the following code fragment:

double answer = 13 / 5;

System.out.println("13 / 5 = " + answer);

The output is:

13 / 5 = 2.0

The programmer intends the output to be:

13 / 5 = 2.6

Which of the following replacements for the first line of code will NOT fix the problem?

• double answer = (double) 13 / 5;

• double answer = 13 / (double) 5;

• double answer = 13.0 / 5;

• double answer = 13 / 5.0;

• double answer = (double) (13 / 5);

What value is stored in result if:

int result = 13 - 3 * 6 / 4 % 3;

• -5

• 0

• 13

• -1

• 12

Suppose that addition and subtraction had higher precedence than multiplication and division. Then the expression:

2 + 3 * 12 / 7 - 4 + 8

would evaluate to which of the following?

• 11

• 12

• 5

• 9

• -4

Which is true of the following boolean expression, given that x is a variable of type double?

3.0 == x * (3.0 / x)

• It will always evaluate to false.

• It may evaluate to false for some values of x.

• It will evaluate to false only when x is zero.

• It will evaluate to false only when x is very large or very close to zero.

• It will always evaluate to true.

Which of the following will evaluate to true only if boolean expressions

A, B, and C are all false?

• !A && !(B && !C)

• !A || !B || !C

• !(A || B || C)

• !(A && B && C)

• !A || !(B || !C)

Assume that a and b are integers. The boolean expression

!( a <= b) && (a * b > 0)

will always evaluate to true given that

• a = b

• a > b

• a < b

• a > b and b > 0

• a > b and b < 0

Given that a, b, and c are integers, consider the boolean expression

(a < b) || !((c == a * b) && (c < a))

Which of the following will guarantee that the expression is true?

• c < a is false.

• c < a is true.

• a < b is false.

• c == a * b is true.

• c == a * b is true, and c < a is true.