Programming Quiz 1 & 2

18) Which one of the following operators computes the remainder of an integer division?

%

22) Which one of the following is a correct representation of the given mathematical expression in Java? a + b/ 2

(a + b) / 2

25) Which operator is used to concatenate two or more strings?

+

11) What is the value inside the value variable at the end of the given code snippet? public static void main(String[] args) { int value = 3; value = value - 2 * value; value++; }

-2

50) What is the output of the following code snippet? public static void main(String[] args) { int num1 = 10; int num2 = 5; int num3 = 200; num3 = num3 % (num1 * num2); System.out.println(num3); }

0

26) What output is produced by these statements? String name = "Joanne Hunt"; System.out.println(name.length());

11

60) What (if any) type of error occurs with the following code if the user input is ABC? public static void main(String[] args) { Scanner in = new Scanner(System.in); System.out.print("Enter a number: "); String str = in.next(); int count = Integer.parseInt(str); System.out.println("Input is " + count); }

Run-time error

62) What does the following statement sequence print? String str = "Hello"; int n = str.length(); String mystery = str.substring(0, 1) + str.substring(n - 2, n + 1); System.out.println(mystery);

Run-time error

80. What is the difference between the result of the following two Java statements? I. int cents = (int)(100 * price + 0.5); II. int cents = (100 * price + 0.5);

Statement I compiles, but II does not

86) Suppose a phone number, stored as a ten-character string (of digits only) called phoneNumber, must be converted into a string that has parentheses around the area code. Which statement below will do that?

String newNumber = "(" + phoneNumber.substring(0, 3) + ")" + phoneNumber.substring(3, 10);

56) Which one of the following statements displays the output as (1.23e+02)?

System.out.printf("%(5.2e", -123.0);

55) Which one of the following statements displays the output as 54321.00?

System.out.printf("%8.2f", 54321.0);

58) Which one of the following statements displays the output as +00321.00?

System.out.printf("+%09.2f", 321.0);

46) Which of the given System.out.print statements generates the following output? ABCDE"\

System.out.println("ABCDE\"\\");

47) Which of the given statements generates the following output? \\\"///

System.out.println("\\\\\\\"///");

4) What is wrong with the following code snippet? int average; average = 78A;

The average variable is assigned a non-numeric value.

93) What is wrong with the following code snippet? int size = 42; cost = 9.99; System.out.println("size = " + size); System.out.println(" cost = " + cost);

The code snippet uses a variable that has not been declared.

3) What is wrong with the following code snippet? public class Area { public static void main(String[] args) { int width = 10; height = 20.00; System.out.println("area = " + (width * height)); } }

The code snippet uses an undeclared variable.

76) What is the output of the following code snippet? int counter = 0; counter++; System.out.print("The initial value of the counter is "); System.out.println(count);

The code will not compile

32) What happens to the fractional part when a division is performed on two integer variables?

The fractional part is discarded.

40) Assuming that the user inputs a value of 25000 for the pay and 10 for the bonus rate in the following code snippet, what is the output? public static void main(String[] args) { Scanner in = new Scanner(System.in); System.out.print("Enter the pay: "); double pay = in.nextDouble(); System.out.print("Enter the bonus rate: "); double bonus = in.nextDouble(); System.out.println("The new pay is " + (pay + pay * (bonus / 100.0))); }

The new pay is 27500

27) How do you compute the length of the string str?

str.length()

45) How do you extract the first 5 characters from the string str?

str.substring(0, 5)

52) Which one of the following statements can be used to extract the last 10 characters from the string variable str?

str.substring(str.length() - 10, str.length())

39) Which one of the following statements can be used to extract the last five characters from any string variable str?

str.substring(str.length() - 5, str.length())

48) What will be the value inside the variables x and y after the given set of assignments? int x = 20; int y = 10; x = (x - y) * 2; y = x / 2;

x = 20, y = 10

31) Which one of the following refers to a number constant that appears in code without explanation?

Magic number

36) Which one of the following statements gives the absolute value of the floating-point number x = -25.50?

Math.abs(x);

59) One way to avoid round-off errors is to use:

Math.round()

64) What does the following statement sequence print? final String str = "Java"; str += " is powerful"; System.out.println(str);

Nothing; compile-time error

33) Consider the following division statements: I. 22 / 7 II. 22.0 / 7 III. 22 / 7.0 Which of the following is correct?

Only I will return an integer value.

38) Which of the methods below are static methods? I. length II. Substring III. Pow IV. sqrt

Only III and IV

89) Consider the following Java variable names: I. 1stInstance II. basicInt% III. empName_ IV. addressLine1 V. DISCOUNT Which of the following options is correct?

Only III, IV, and V are valid Java variable names.

67) What does the following statement sequence print if the user input is 123? public static void main(String[] args) { Scanner in = new Scanner(System.in); System.out.print("Enter a number: "); String str = in.next(); str += 456; System.out.println(str); }

123456

41) What is the value of Math.abs(-2)?

2

6) What will be the value stored in the variable x after the execution of the following code snippet? int a = 10; int b = 20; int c = 2; int x = b / a /*c*/;

2

79) What is result of evaluating the following expression? (45 / 6) % 5

2

51) Assuming that the user enters 23 and 45 as inputs for num1 and num2, respectively, what is the output of the following code snippet? public static void main(String[] args) { Scanner in = new Scanner(System.in); System.out.print("Enter a number: "); String num1 = in.next(); System.out.print("Enter another number: "); String num2 = in.next(); System.out.println(num1 + num2); }

2345

74) What is the output of this code snippet? int sum = 22; sum = sum + 2; System.out.print(sum); // sum = sum + 4; System.out.print(sum);

2424

42) What is the output of the following code snippet? public static void main(String[] args) { double x; x = Math.pow(3.0, 2.0) + Math.pow(4.0, 2.0); System.out.println(x); }

25.0

49) What is the value inside the var variable at the end of the given code snippet? public static void main(String[] args) { int var = 30; var = var + 2 / var; var++; }

31

29) What is the output of the following code snippet? public static void main(String[] args) { int s; double f = 365.25; s = f / 10; System.out.println(s); }

36

14) What is the output of the following code snippet? public static void main(String[] args) { int value = 3; value++; System.out.println(value); }

4

37) Assuming that the user enters 45 and 62 as inputs for n1 and n2, respectively, what is the output of the following code snippet? public static void main(String[] args) { System.out.print("Enter a number: "); Scanner in = new Scanner(System.in); String n1 = in.next(); System.out.print("Enter another number: "); String n2 = in.next(); String result = n1 + n2; System.out.print(result); }

4562

15) What is the output of the following code snippet? public static void main(String[] args) { int value = 25; value = value * 2; value--; System.out.println(value); }

49

66) What does the following statement sequence print if the user input is 123? public static void main(String[] args) { Scanner in = new Scanner(System.in); System.out.print("Enter a number "); int myInt = in.nextInt(); myInt += 456; System.out.println(myInt); }

579

13) What is the result of the following expression? double d = 2.5 + 4 * -1.5 - (2.5 + 4) * -1.5;

6.25

20) What is the output of the following code snippet? public static void main(String[] args) { double a; a = Math.sqrt(9.0) + Math.sqrt(16.0); System.out.println(a); }

7.0

19) What is the value of Math.pow(3, 2)?

9

5) Which of the following guidelines will make code more explanatory for others?

Add comments to source code

99) Which one of the following types of statements is an instruction to replace the existing value of a variable with another value?

Assignment

82) At what point in the problem-solving process should one write pseudocode?

Before writing Java code, as a guide for a general solution

100) What is the meaning of x = 0; in Java?

It sets the variable x to zero

84) What is the output of the following code snippet? String firstname = "William"; String lastname; System.out.println("First: " + first); System.out.println("Last: " + lastname);

Code will not compile

68) What is the output of the following statement sequence? public static void main(String[] args) { int x = 100.0 % 6.0; System.out.println(x); }

Compile-time error

65) What does the following statement sequence print? String str = "Java"; str += " is powerful"; System.out.println(str);

Java is powerful

30) Assuming that the user inputs "Joe" at the prompt, what is the output of the following code snippet? public static void main(String[] args) { System.out.print("Enter your name "); String name; Scanner in = new Scanner(System.in); name = in.next(); name += ", Good morning"; System.out.print(name); }

Joe, Good morning

91) What is the result of the following code snippet? double bottles; double bottleVolume = bottles * 2; System.out.println(bottleVolume);

Does not compile

63) What does the following statement sequence print? String str = "Java Is Good"; int n = str.length(); String mystery = str.substring(n - 4, n) + str.charAt(4) + str.substring(0, 4); System.out.println(mystery);

Good Java

61) What does the following statement sequence print? String str = "Harry"; int n = str.length(); String mystery = str.substring(0, 1) + str.substring(n - 2, n); System.out.println(mystery);

Hry

77) Which statements about numeric types in Java are true? I. There is more than one integer type II. The data type float uses twice the storage of double III. The numeric range of the Java integer type is related to powers of two

I, III

73) Which of the following statements about constants in Java are true? I. Although not required, constants are commonly named using uppercase letters II. Only integer values can appear as constants III. A variable can be defined with an initial value, but the reserved word final prevents it from being changed IV. A named constant makes computations that use it clearer

I, III, IV

7) Which of the following statements with comments is(are) valid? I. int cnt = 0; /* Set count to 0 II. int cnt = 0; /* Set count to 0 */ III. int cnt = 0; // Set count to 0

II and III are valid

8) What is wrong with the following code? int count = 2000 * 3000 * 4000;

Integer overflow

70) Which statement about number literals in Java is false?

Integers must be positive

85) What is the correct way to invoke methods on variables in Java that are strings?

Invoke them using the variable name and the dot (.) notation.

69) Which statement is true?

It is incorrect to initialize a string variable with a number

16) Assuming that the user inputs a value of 25 for the price and 10 for the discount rate in the following code snippet, what is the output? public static void main(String[] args) { Scanner in = new Scanner(System.in); System.out.print("Enter the price: "); double price = in.nextDouble(); System.out.print("Enter the discount rate: "); double discount = in.nextDouble(); System.out.println("The new price is " + price - price * (discount / 100.0)); }

The new price is 22.5

97) What is wrong with the following code snippet? int price; price = 9.42;

The price variable is assigned a decimal value.

24) What is the result of the following statement? String s = "You" + "had" + "me" + "at" + "hello";

The string s has the following value: "Youhadmeathello"

34) Which of the following options is valid with reference to the code snippet? public static void main(String[] args) { double d = 45.326; double r = d % 9.0; System.out.println(r); }

The value inside the variable r will be 0.326

35) What is the output of the following code snippet? public static void main(String[] args) { int var1 = 10; int var2 = 2; int var3 = 20; var3 = var3 / (var1 % var2); System.out.println(var3); }

There will be no output due to a run-time error.

88) Which statement is true about variable names in Java?

They can contain an underscore symbol ("_")

81) The first step in problem solving is

To understand the problem and its inputs and outputs

75) What is the output of this code snippet? double average; int grade1 = 87; int grade2 = 94; // System.out.print("The average is " + (grade1 + grade2) / 2.0); System.out.print("The average is " + average);

Unpredictable result

28) What is the output of the following code snippet? public static void main(String[] args){ { String str1; str1 = "I LOVE MY COUNTRY"; String str2 = str1.substring(4, 9); System.out.println(str2); }

VE MY

90) Which is the appropriate time to initialize a variable?

When you define it

17) Which of the following statements is correct about constants?

You can make a variable constant by using the final reserved word when declaring it.

10) What will be the value inside the variables a and b after the given set of assignments? int a = 20; int b = 10; a = (a + b) / 2; b = a; a++;

a = 16, b = 15

98.) Which one of the following is an assignment statement?

a = 20;

71) Which option represents the best choice for a variable name to represent the average grade of students on an exam?

averageGrade

23) Which of the following is the Java equivalent of the following mathematical expression? c = 2pi * radius

c = 2 * Math.PI * radius;

43) Which is the Java equivalent of the following mathematical expression? c = (√a + √b)2

c = Math.pow((Math.sqrt(a) + Math.sqrt(b)), 2);

21) Which is the Java equivalent of the following mathematical expression? c = √(a2 + b2)

c = Math.sqrt(Math.pow(a, 2) + Math.pow(b, 2));

54) Which one of the following statements can be used to get the fifth character from a string str?

char c = str.charAt(4);

2) What is the result of the following code snippet? public static void main(String[] args { double circleRadius; double circleVolume = 22 / 7 * circleRadius * circleRadius; System.out.println(circleVolume); }

compile-time error

96) In an airline reservation system, the cost of an airline ticket is required. Which data type should be used to store this value?

double

53) Which one of the following statements can be used to convert a string str to a double?

double n = Double.parseDouble(str);

9) Which one of the following variables is assigned with valid literals?

double salary2 = 0; salary2 = 2.96E-2;

57) Which one of the following statements defines a constant with the value 123?

final int MY_CONST = 123;

1) Which of the following options declares a float variable?

float age;

83) The problem solving process emphasizes a "first, do-it-by-hand" approach because

if programmers cannot compute a solution by hand, it is unlikely they will be able to write a program that can do it.

94) Which one of the following reserved words is used in Java to represent a value without a fractional part?

int

95) In an airline reservation system, the number of available seats in an airplane is required. Which data type should be used to store this value?

int

87) Which of the following options defines an integer variable?

int age;

92) Which one of the following is a correct method for defining and initializing an integer variable with name value?

int value = 30;

12.) What are the values of num1 and num2 after this snippet executes? double num1 = 4.20; double num2 = num1 * 10 + 5.0;

num1 = 4.20 and num2 = 47.0

44) Which of the following is the Java equivalent of the following mathematical expression? p = 2 * pi * (radius)^3

p = 2 * Math.PI * Math.pow(radius, 3);

72) The assignment operator

places a new value into a variable