CSC 151 Chapter 2

JAVA PROGRAMMING

24 % 5 is ________

4

What is y displayed in the following code?

public class Test {

 public static void main(String[] args) {

 int x = 1;

 int y = x++ + x;

 System.out.println("y is " + y);

 } 

}

y is 3

Which of the following is a valid identifier? Please select all that apply.

radius & $343

According to Java naming convention, which of the following names can be variables? Please select all that apply.

findArea & totalLength

To assign a double variable d to a float variable x, you write ________.

x = (float)d;

Are the following four statements equivalent?

 number += 1;

 number = number + 1;

 number++;

 ++number;

Yes

Which of the following expression results in 45.37?

(int)(45.378 * 100) / 100.0

What is x after the following statements?

int x = 2;

int y = 1;

x *= y + 1;

x is 4

To add number to sum, you write ________. (Note: Java is case-sensitive) Please select all that apply.

sum += number;

Suppose x is 1. What is x after x -= 1?

0

25 % 1 is ________

0

If you attempt to add an int, a byte, a long, and a double, the result will be a(n) ________ value.

double

The expression (int)(76.0252175 * 100) / 100 evaluates to ________.

76

-25 % 5 is ________

0

Which of the following are correct names for variables according to Java naming conventions? Please select all that apply.

radius & findArea

Which of the following assignment statements is incorrect? Please select all that apply.

i = 1 = j = 1 = k = 1;

i == j == k == 1;

Which of the following is incorrect?

float x = 1.0;

Suppose x is 1. What is x after x += 2?

3

To declare a constant MAX_LENGTH inside a method with value 99.98, you write ________.

final double MAX_LENGTH = 99.98;

What is the value of (double)5/2?

2.5

The System.currentTimeMillis() returns ________.

the current time in milliseconds since midnight, January 1, 1970 GMT (the Unix time)

Suppose a Scanner object is created as follows, what method do you use to read a real number?

Scanner input = new Scanner(System.in);

input.nextDouble();

What is the output of the following code?

double x = 5.5;

int y = (int)x;

System.out.println("x is " + x + " and y is " + y);

x is 5.5 and y is 5

Which of the following is a constant, according to Java naming conventions? Please select all that apply.

COUNT

MAX_VALUE

The expression 4 + 20 / (3 - 1) * 2 is evaluated to ________.

24

Which of these data types requires the most amount of memory?

long

-24 % 5 is ________

-4

Which of the following expression results in a value 1?

37 % 6

Which of the following expressions will yield 0.5? Please select all that apply.

1.0 / 2

1 / 2.0

(double) 1 / 2

What is y displayed?

public class Test {

 public static void main(String[] args) {

 int x = 1;

 int y = x + x++;

 System.out.println("y is " + y);

 } 

}

y is 2

If you enter 1 2 3, when you run this program, what will be the output?

import java.util.Scanner;

public class Test1 {

 public static void main(String[] args) {

 Scanner input = new Scanner(System.in);

 System.out.print("Enter three numbers: ");

 double number1 = input.nextDouble();

 double number2 = input.nextDouble();

 double number3 = input.nextDouble();

 // Compute average

 double average = (number1 + number2 + number3) / 3;

 // Display result

 System.out.println(average);

 }

}

2.0

What is the value of (double)(5/2)?

2.0

What is the exact output of the following code?

 double area = 3.5;

 System.out.print("area");

 System.out.print(area);

area3.5

The following code fragment reads in two numbers. What is the incorrect way to enter these two numbers?

Scanner input = new Scanner(System.in);

int i = input.nextInt();

double d = input.nextDouble();

Enter a numeric value with a decimal point, a space, an integer, and then the Enter key.

How do you write 2.5 ^ 3.1 in Java?

Math.pow(2.5, 3.1)

________ is the Java assignment operator.

=

To improve readability and maintainability, you should declare a ________ for PI instead of using literal values such as 3.14159.

constant

Which of the following are correct ways to declare variables? Please select all that apply.

int length, width;

int length; int width;

-24 % -5 is ________

-4

True or False? Every letter in a Java keyword is in lowercase.

True

To assign a value 1 to variable x, you write ________.

x = 1;

________ is the code with natural language mixed with Java code.

Pseudocode

To add a value 1 to variable x, you write ________. Please select all that apply.

x = x + 1;

x = 1 + x;

x += 1;

What is i printed?

public class Test {

 public static void main(String[] args) {

 int j = 0;

 int i = ++j + j * 5;

 System.out.println("What is i? " + i);

 }

}

6

What is i printed in the following code?

public class Test {

 public static void main(String[] args) {

 int j = 0;

 int i = j++ + j * 5;

 System.out.println("What is i? " + i);

 }

}

5

What is the result of 45 / 4?

11

What is x after the following statements?

int x = 1;

x *= x + 1;

x is 2

Which of the following statements are the same?

(A) x -= x + 4

(B) x = x + 4 - x

(C) x = x - (x + 4)

(A) and (C) are the same.

To obtain the current second, use ________.

System.currentTimeMillis() / 1000 % 60

Which of the following assignment statements is illegal?

int t = 4.5;