D3 - M

What is y after the following statement is executed? x = 0; y = (x > 0) ? 10 : -10; a. -10 b. 0 c. 10 d. 20 e. Illegal expression

a

Which of the following expressions evaluates to true? a. 'a' > 'A' b. 34 > 34 c. 'A' > 'z' d. 2 > '2'

a

Suppose x=10 and y=10 what is x after evaluating the expression (y > 10) && (x++ > 10). a. 9 b. 10 c. 11

b

Suppose x=10 and y=10 what is x after evaluating the expression (y >= 10) || (x++ > 10). a. 9 b. 10 c. 11

b

Suppose x=10 and y=10 what is x after evaluating the expression (y >= 10) || (x-- > 10). a. 9 b. 10 c. 11

b

Suppose x=10 and y=10. What is x after evaluating the expression (y > 10) && (x-- > 10)? a. 9 b. 10 c. 11

b

Analyze the following program fragment: int x; double d = 1.5; switch (d) { case 1.0: x = 1; case 1.5: x = 2; case 2.0: x = 3; } a. The program has a compile error because the required break statement is missing in the switch statement. b. The program has a compile error because the required default case is missing in the switch statement. c. The switch control variable cannot be double. d. No errors.

c

The conditional operator ? : is a ______ a. unary operator b. binary operator c. ternary operator

c

Which of the following code displays the area of a circle if the radius is positive. a. if (radius != 0) System.out.println(radius * radius * 3.14159); b. if (radius >= 0) System.out.println(radius * radius * 3.14159); c. if (radius > 0) System.out.println(radius * radius * 3.14159); d. if (radius <= 0) System.out.println(radius * radius * 3.14159);

c

Analyze the following code. int x = 0; if (x > 0); { System.out.println("x"); } a. The symbol x is always printed. b. The value of variable x is always printed. c. Nothing is printed because x > 0 is false. d. The symbol x is always printed twice.

a

Analyze the following code: if (x < 100) && (x > 10) System.out.println("x is between 10 and 100"); a.The statement has compile errors because (x<100) & (x > 10) must be enclosed inside parentheses. b.The statement has compile errors because (x<100) & (x > 10) must be enclosed inside parentheses and the println(...) statement must be put inside a block. c.The statement compiles fine. d.The statement compiles fine, but has a runtime error.

a

Analyze the following two code fragments. (i) int x = 5; if (0 < x) && (x < 100) System.out.println("x is between 1 and 100"); (ii) int x = 5; if (0 < x && x < 100) System.out.println("x is between 1 and 100"); a. The first fragment has a syntax error. b. The second fragment has a syntax error. c. Both fragments produce the same output. d. Both fragments compile, but produce different results.

a

Including a space between the relational operators >=, <=, ==, and != causes a syntax error. a. true b. false

a

Suppose x=0 and y=0 what is x after evaluating the expression (y > 0) && (1 > x++). a. 0 b. -1 c. 1

a

System.exit(0) can be used to terminate the program. a. true b. false

a

The ________ operator can be used to compare two values. a. relational b. boolean c. numerical d. casting

a

The binary operator + is left-associative. a. true b. false

a

What is (int)Math.random()? a. 0 b. 1 c. 0.5 d. 1.1

a

What is 1 + 1 + 1 + 1 + 1 == 5? a. true b. false c. There is no guarantee that 1 + 1 + 1 + 1 + 1 == 5 is true.

a

What is the output from System.out.println((int)Math.random() * 4)? a. 0 b. 1 c. 2 d. 3 e. 4

a

What is the value of the following expression? true || true && false a. true b. false

a

Which of the following is equivalent to x != y? a. ! (x == y) b. x > y && x < y c. x > y || x < y d. x >= y || x <= y

a

You can always convert a switch statement to an equivalent if statement. a. true b. false

a

A break statement is required for a switch-case statement in Java. a. true b. false

b

Analyze the following code. int x = 0; int y = ((x < 100) && (x > 0)) ? 1: -1; a. y becomes 1 after the code is executed. b. y becomes -1 after the code is executed.

b

Analyze the following code. boolean even = false; if (even) { System.out.println("It is even!"); } a. The code displays It is even! b. The code displays nothing. c. The code is wrong. You should replace if (even) with if (even == true) d. The code is wrong. You should replace if (even) with if (even = true)

b

Assume x = 4 and y = 5, Which of the following is true? a. !(x == 4) ^ y != 5 b. x != 4 ^ y == 5 c. x == 5 ^ y == 4 d. x != 5 ^ y != 4

b

Assume x = 4 and y = 5, Which of the following is true? a. x < 5 && y < 5 b. x < 5 || y < 5 c. x > 5 && y > 5 d. x > 5 || y > 5

b

Given |x - 2| >= 4, Which of the following is true? a. x - 2 >= 4 && x - 2 <= -4 b. x - 2 >= 4 || x - 2 <= -4 c. x - 2 >= 4 && x - 2 < -4 d. x - 2 >= 4 || x - 2 < -4

b

In Java, the word true is ________. a. a Java keyword b. a Boolean literal c. same as value 1 d. same as value 0

b

In a switch statement, the default case must appear last among all cases. Otherwise, it would result in a compilation error. a. true b. false

b

Suppose cond1 and cond2 are two Boolean expressions. When will this if condition be true? if (cond1 && cond2) ... a. in case cond1 is true and cond2 is false b. in case cond1 is true and cond2 is true c. in case cond1 is false and cond2 is false d. in case cond1 is false and cond2 is true

b

Suppose cond1, cond2, and cond3 are Boolean expressions. Which of the following expression is equivalent to cond1 || cond2 && cond3? a. (cond1 || cond2) && cond3 b. cond1 || (cond2 && cond3)

b

Suppose income is 4001, what is the output of the following code: if (income > 3000) { System.out.println("Income is greater than 3000"); } else if (income > 4000) { System.out.println("Income is greater than 4000"); a. no output b. Income is greater than 3000 c. Income is greater than 3000 followed by Income is greater than 4000 d. Income is greater than 4000 e. Income is greater than 4000 followed by Income is greater than 3000

b

Suppose x = 1, y = -1, and z = 1. What is the printout of the following statement? (Please indent the statement correctly first.) if (x > 0) if (y > 0) System.out.println("x > 0 and y > 0"); else if (z > 0) System.out.println("x < 0 and z > 0"); a. x > 0 and y > 0; b. x < 0 and z > 0; c. x < 0 and z < 0; d. no printout.

b

Suppose you write the code to display "Cannot get a driver's license" if age is less than 16 and "Can get a driver's license" if age is greater than or equal to 16. Which of the following code is the best? I: if (age < 16) System.out.println("Cannot get a driver's license"); if (age >= 16) System.out.println("Can get a driver's license"); II: if (age < 16) System.out.println("Cannot get a driver's license"); else System.out.println("Can get a driver's license"); III: if (age < 16) System.out.println("Cannot get a driver's license"); else if (age >= 16) System.out.println("Can get a driver's license"); IV: if (age < 16) System.out.println("Cannot get a driver's license"); else if (age > 16) System.out.println("Can get a driver's license"); else if (age == 16) System.out.println("Can get a driver's license"); a. I b. II c. III d. IV

b

The "less than or equal to" comparison operator in Java is __________. a. < b. <= c. =< d. << e. !=

b

The assignment operator = is left-associative. a. true b. false

b

The break keyword must be used in a switch statement; otherwise, a syntax error occurs. a. true b. false

b

The default case must be specified in a switch statement. a. true b. false

b

The exclusive or (^) of true and true is true. a. true b. false

b

The not equal comparison operator in Java is __________. a. <> b. != c. != = d. ^=

b

What is the output of the following code? boolean even = false; System.out.println((even ? "true" : "false")); a. true b. false c. nothing d. true false

b

What is x after evaluating x = (2 > 3) ? 2 : 3; a. 2 b. 3 c. 4 d. 5

b

What is y after the following switch statement is executed? int x = 3; int y = 4; switch (x + 3) { case 6: y = 0; case 7: y = 1; default: y += 1; } a. 1 b. 2 c. 3 d. 4 e. 0

b

What is y after the following switch statement? int x = 0; int y = 0; switch (x + 1) { case 0: y = 0; case 1: y = 1; default: y = -1 } a. 1 b. -1 c. 0 d. 2

b

Which of the following expression is equivalent to (x > 1). a. x >= 1 b. !(x <= 1) c. !(x = 1) d. !(x < 1)

b

Which of the following is a possible output from invoking Math.random()? a. 3.43 b. 0.5 c. -0.1 d. 1.0

b

Which of the following is the correct expression that evaluates to true if the number x is between 1 and 100 or the number is negative? a. 1 < x < 100 && x < 0 b. ((x < 100) && (x > 1)) || (x < 0) c. ((x < 100) && (x > 1)) && (x < 0) d. (1 > x > 100) || (x < 0)

b

You can always convert an if statement to a switch statement. a. true b. false

b

You can cast a Boolean value to an int, or an int to Boolean. a. true b. false

b

Analyze the following code: // Enter an integer Scanner input = new Scanner(System.in); int number = input.nextInt(); if (number <= 0) System.out.println(number); a. The if statement is wrong, because it does not have the else clause; b. System.out.println(number); must be placed inside braces; c. If number is zero, number is displayed; d. If number is positive, number is displayed. e. number entered from the input cannot be negative.

c

Analyze the following fragment. double x = 0; double d = 1; switch (d + 4) { case 5: x++; case 6: --x; } a. The required break keyword is missing in the switch statement. b. The required default keyword is missing in the switch statement. c. The switch control variable cannot be double. d. d + 4 should be replaced by 5.

c

Assume x is 0. What is the output of the following statement? if (x > 0) System.out.print("x is greater than 0"); else if (x < 0) System.out.print("x is less than 0"); else System.out.print("x equals 0"); a. x is greater than 0 b. x is less than 0 c. x equals 0 d. None

c

Given |x - 2| <= 4, Which of the following is true? a. x - 2 <= 4 && x - 2 >= 4 b. x - 2 <= 4 && x - 2 > -4 c. x - 2 <= 4 && x - 2 >= -4 d. x - 2 <= 4 || x - 2 >= -4

c

Suppose isPrime is a boolean variable, which of the following is the correct and best statement for testing if isPrime is true. a. if (isPrime = true) b. if (isPrime == true) c. if (isPrime) d. if (!isPrime = false) e. if (!isPrime == false)

c

The __________ method immediately terminates the program. a. System.terminate(0); b. System.halt(0); c. System.exit(0); d. System.quit(0); e. System.stop(0);

c

The equal comparison operator in Java is __________. a. <> b. != c. == d. ^=

c

The following code displays ___________. double temperature = 50; if (temperature >= 100) System.out.println("too hot"); else if (temperature <= 40) System.out.println("too cold"); else System.out.println("just right"); a. too hot b. too cold c. just right d. too hot too cold just right

c

The order of the precedence (from high to low) of the operators binary +, *, &&, ||, & is: a. &&, ||, &, *, + b. *, +, &&, ||, & c. *, +, &, &&, || d. *, +, &, ||, && e. &, ||, &&, *, +

c

What is 1 - 1.0 - 1.0 - 1.0 - 1.0 - 1.0 == 5.0? a. true b. false c. There is no guarantee that 1 - 1.0 - 1.0 - 1.0 - 1.0 - 1.0 == 5.0 is true.

c

What is 1.0 + 1.0 + 1.0 == 3.0? a. true b. false c. There is no guarantee that 1.0 + 1.0 + 1.0 == 3.0 is true.

c

What is y displayed in the following code? public class Test1 { public static void main(String[] args) { int x = 1; int y = x = x + 1; System.out.println("y is " + y); } } a. y is 0. b. y is 1 because x is assigned to y first. c. y is 2 because x + 1 is assigned to x and then x is assigned to y. d. The program has a compile error since x is redeclared in the statement int y = x = x + 1.

c

Analyze the following code: Code 1: int number = 45; boolean even; if (number % 2 == 0) even = true; else even = false; Code 2: boolean even = (number % 2 == 0); a. Code 1 has compile errors. b. Code 2 has compile errors. c. Both Code 1 and Code 2 have compile errors. d. Both Code 1 and Code 2 are correct, but Code 2 is better.

d

Analyze the following code: boolean even = ((231 % 2) == 0); if (even = true) System.out.println("It is even!"); else System.out.println("It is odd!"); a. The program has a syntax error b. The program has a runtime error c. The program displays "It is odd!" d. The program displays "It is even!"

d

Analyze the following code: boolean even = false; if (even = true) { System.out.println("It is even!"); } a. The program has a compile error. b. The program has a runtime error. c. The program runs fine, but displays nothing. d. The program runs fine and displays It is even!.

d

Assume x = 4, Which of the following is true? a. !(x == 4) b. x != 4 c. x == 5 d. x != 5

d

What is the output of the following code: (Please indent the statement correctly first.) int x = 9; int y = 8; int z = 7; if (x > 9) if (y > 8) System.out.println("x > 9 and y > 8"); else if (z >= 7) System.out.println("x <= 9 and z >= 7"); else System.out.println("x <= 9 and z < 7"); a. x > 9 and y > 8; b. x <= 9 and z >= 7; c. x <= 9 and z < 7; d. none

d

Which of the Boolean expressions below has incorrect syntax? a. (true) && (3 > 4) b. !(x > 0) && (x > 0) c. (x > 0) || (x < 0) d. (x != 0) || (x = 0)

d

Analyze the following code fragments that assign a boolean value to the variable even. Code 1: if (number % 2 == 0) even = true; else even = false; Code 2: even = (number % 2 == 0) ? true: false; Code 3: even = number % 2 == 0; a. Code 2 has a compile error, because you cannot have true and false literals in the conditional expression. b. Code 3 has a compile error, because you attempt to assign number to even. c. All three are correct, but Code 1 is preferred. d. All three are correct, but Code 2 is preferred. e. All three are correct, but Code 3 is preferred.

e

Analyze the following code: // Enter an integer Scanner input = new Scanner(System.in); int number = input.nextInt(); if (number <= 0) System.out.println(number); System.out.println(number); a. number is always printed out at least once; b. number is printed out twice if number is zero; c. number is printed out twice if number is negative; d. number is printed out once if number is positive. e. All the above.

e

Suppose cond1 and cond2 are two Boolean expressions. When will this if condition be true? if (cond1 || cond2) ... a. in case cond1 is true and cond2 is false b. in case cond1 is true and cond2 is true c. in case cond1 is false and cond2 is false d. in case cond1 is false and cond2 is true e. A,B & D

e

Suppose you write the code to display "Cannot get a driver's license" if age is less than 16 and "Can get a driver's license" if age is greater than or equal to 16. Which of the following code is correct? I: if (age < 16) System.out.println("Cannot get a driver's license"); if (age >= 16) System.out.println("Can get a driver's license"); II: if (age < 16) System.out.println("Cannot get a driver's license"); else System.out.println("Can get a driver's license"); III: if (age < 16) System.out.println("Cannot get a driver's license"); else if (age >= 16) System.out.println("Can get a driver's license"); IV: if (age < 16) System.out.println("Cannot get a driver's license"); else if (age > 16) System.out.println("Can get a driver's license"); else if (age == 16) System.out.println("Can get a driver's license"); a. I b. II c. III d. IV e. All the above

e

What is the possible output from System.out.println((int)Math.random() * 4)? a. 0 b. 1 c. 2 d. 3 e. A,B,C & D

e

Which of the following expression is equivalent to (year % 4 == 0 && year % 100 != 0) || (year % 400 == 0)? a. year % 4 == 0 && year % 100 != 0 || year % 400 == 0 b. (year % 4 == 0) && (year % 100 != 0) || (year % 400 == 0) c. (year % 4 == 0) && (year % 100 != 0 || year % 400 == 0) d. year % 4 == 0 && (year % 100 != 0) || year % 400 == 0 e. A, B & D

e

Which of the following is not a valid boolean expression. a. (1 < x < 100) b. (x = 1) || (x != 1) c. (x =< 5) && (x>=5) d. x == 1 e. A,B & C

e

Which of the following operators are right-associative. a. * b. + (binary +) c. % d. && e. =

e