Programming Midterm Review

The following statement should determine whether count is within the range of 0 through 100. What relational operation should be used? if (count >= 0 ___ count <= 100)

&&

What is the output of the below code: for (int i = 1; i < 5; i++) { int j = 0; while (j < i) { System.out.print(j); j++; } System.out.println(""); }

0 01 012 0123

What will the following code segments print on the screen? int freeze = 32, boil = 212; freeze = 0; boil = 100; System.out.println(freeze + "\n"+ boil + "\n");

0 100

How many String objects does Java creates from the below code: String greeting1 = "Hello Class"; String greeting2 = "Hello Class";

1

Match the conditional expression with the if-else statement that performs the same operation. 1) q = x < y ? a + b : x * 2; 2) q = x < y ? 0 : 1; 3) q = x < y ? x * 2 : a + b; 4) q = x < y ? x * 2 : a - b;

1) if (x < y) q = a + b; else q = x * 2; 2) if (x < y) q = 0; else q = 1; 3) if (x < y) q = x * 2; else q = a + b; 4) if (x < y) q = x * 2; else q = a - b;

The value of x after the following code is executed? will be _____ int x = 10; while (x < 100) { x += 100; }

110

What will the following code segments print on the screen? int a, x = 23; a = x % 2; System.out.println(x + "\n" + a);

23 1

What is the result of the following expression? 10 + 5 * 3 - 20

5

Which of the following are not valid assignment statements? (Indicate all that apply.) total = 9; 72 = amount; profit = 129 letter = 'W';

72 = amount; profit = 129

What will the following code segments print on the screen? System.out.print("Be careful\n)"; System.out.print("This might/n be a trick "); System.out.println("question.");

Be careful This might/n be a trick question.

Java is a platform dependent.

False

What is the output of the below code? int key = 5; switch (key + 1) { case 1: System.out.println("Apples"); break ; case 2: System.out.println("Oranges"); break ; case 3: System.out.println("Peaches"); case 4: System.out.println("Plums"); break ; default : System.out.println("Fruitless"); }

Fruitless

What will the following code segments print on the screen? System.out.print("I am the incredible"); System.out.print("computing\nmachine"); System.out.print("\nand I will\namaze\n)"; System.out.println("you.");

I am the incrediblecomputing machine and I will amaze you.

How many time the below loop will be executed? int count = 0; while (count < 10){System.out.println("I love Java Programming!");

Infinite

What are the three types of loops statements that Java provides.

Java provides three types of loop statements: while loops, do-while loops, and for loops.

What is the output of the below code? int key = 1; switch (key + 1) { case 1: System.out.println("Apples"); break ; case 2: System.out.println("Oranges"); break ; case 3: System.out.println("Peaches"); case 4: System.out.println("Plums"); break ; default : System.out.println("Fruitless"); }

Oranges

what is the output of the below code? int key = 3; switch (key + 1) { case 1: System.out.println("Apples"); break ; case 2: System.out.println("Oranges"); break ; case 3: System.out.println("Peaches"); case 4: System.out.println("Plums"); break ; default : System.out.println("Fruitless"); }

Plums

What is the output produced by the following code? char letter = 'B'; switch (letter) { case 'A': case 'a': System.out.println("Some kind of A."); case 'B': case 'b': System.out.println("Some kind of B."); break; default : System.out.println("Something else."); break;}

Some kind of B

Which of the following are not valid println statements? (Indicate all that apply.) System.out.println + "Hello World"; System.out.println("Have a nice day"); out.System.println(value); println.out(Programming is great fun);

System.out.println + "Hello World"; out.System.println(value); println.out(Programming is great fun);

What would the below code outputs average = 50; if (average > 95); System.out.println("Your avg score is high!"); System.out.println("The average is " + average);

The average is 50.0 Your avg score is high!

In a nested loop, the inner loop goes through all of its iterations for every iteration of the outer loop.

True

The for loop generally is used to execute a loop body a fixed number of times.

True

The while loop and the do-while loop often are used when the number of repetitions is not predetermined.

True

What is the output of the below code: String sample = "AbcdefG"; System.out.println(sample.substring(2,5));

cde

The below line is known as a: public class Simple

class header

Variables are classified according to their

data types

This type of loop always executes at least once.

do-while

Write a program to calculate the area of a circle as follows: Assign the circle radius. Compute the area using this formula: area = radius X radius X 3.14159 Display the area. Below is a sample output if how the output should look: The area for the circle of radius 10.0 is 314.159

double circleArea; //The area of a circle. double radius = 10.0; //The radius of a circle. circleArea = radius * radius * 3.14159; System.out.print("The area for the circle "); System.out.print("of radius " + radius); System.out.print(" is " + circleArea);

Convert the following pseudocode to Java code. Be sure to declare the appropriate data type variables. Store 2000.50 in expense variable Store 10000.0 in revenue variable Subtract expense from revenue and Store the result in netIncome variable. Display the results

double netIncome; double expense = 2000.50; double revenue = 10000.0; netIncome = revenue - expense; System.out.print(netIncome); Output: 7999.5

String name1 = "Mark"; String name2 = new String("Mark"); System.out.println(name1 == name2); The output of the above code will be _________

false

The while loop executes the loop body first and then checks the loop-continuation-condition to decide whether to continue or to terminate.

false

Constants in Java are declared using the _______ keyword

final

Convert the below loop to a for loop: int count = 0; while(count < 5) { System.out.println(count +": Welcome to Java"); count++; }

for (count=0; count< 5; count++ ) { System.out.println(count +": Welcome to Java"); }

Which of the following for loops headers can produce the below output of num/denom: 1/15 2/14 3/13 4/12 5/11 6/10 7/9 8/8 9/7 10/6 11/5 12/4 13/3 14/2 15/1

for (int num = 1, denom = 15; num <= 15; num++, denom--) System.out.print(num + "/" + denom + " ");

Which loop is considered to be count-controlled loop.

for loop

Java is a ___________, general-purpose object-oriented programming (OOP) language.

high level

What is the correct if-else statement that assigns 0.10 to commission unless sales is greater than or equal to 50000.0, in which case it assigns 0.2 to commission.

if (sales <= 5000.0) commission = 0.2; else commission = 0.10;

Which one of the below boolean expressions is accurate and most appropriate to use. if(even = true) System.out.println("It is even"); if(even == true) System.out.println("It is even"); if(even) System.out.println("It is even"); if(even === true) System.out.println("It is even");

if(even === true) System.out.println("It is even");

Write a program that would prompt the user to enter an integer. The program then would displays a table of squares and cubes from 1 to the value entered by the user. The program should prompt the user to continue if they wish. Use these formulas for calculating squares and cubes are: square = x * x cube = x * x * x Assume that the user will enter a valid integer. The application should continue only if the user enters "y" or "Y" to continue. Sample Output: Welcome to the Squares and Cubes table Enter an integer: 4 Number Squared Cubed --------------------- 1 1 1 2 4 8 3 9 27 4 16 64 Continue? (y/n): y Enter an integer: 16 Number Squared Cubed --------------------- 1 1 1 2 4 8 3 9 27 4 16 64 5 25 125 6 36 216 7 49 343 8 64 512 9 81 729 10 100 1000 11 121 1331 12 144 1728 13 169 2197 14 196 2744 15 225 3375 16 256 4096 Continue? (y/n): n

import java.util.Scanner; public class NumberPowers { public static void main(String[] args) { // display a welcome message System.out.println("Welcome to the Squares and Cubes table\n"); // create the Scanner object Scanner sc = new Scanner(System.in); // perform conversions until choice isn't equal to "y" or "Y" String choice = "y"; while (choice.equalsIgnoreCase("y")) { // get an int from the user System.out.print("Enter an integer: "); int num = Integer.parseInt(sc.nextLine()); System.out.println(); // define the table and append the header rows String table = ""; table += "Number\tSquared\tCubed\n"; table += "======\t=======\t=====\n"; // appends the rest of the rows to the table for (int i = 1; i <= num; i++) { int square = i * i; int cube = i * i * i; table += i + "\t" + square + "\t" + cube + "\n"; } // display the table System.out.println(table); // see if the user wants to continue System.out.print("Continue? (y/n): "); choice = sc.nextLine(); System.out.println(); } sc.close(); } }

Write a do-while loop that asks the user to enter two numbers. Sum the two numbers and display the output.Ask the user whether or not wishes to perform the operation again, otherwise terminate the program. Sample output: Enter first number: 4 Enter second number: 5 The sum of the two numbers is : 9.0 Do you wish to do this again? (Y/N) y Enter first number: 19 Enter second number: 39 The sum of the two numbers is : 58.0 Do you wish to do this again? (Y/N) n

import java.util.Scanner; public class NumberSum { public static void main(String[] args) { // Declare variables double number1, number2; char choice; // Create s Scanner class object Scanner scn = new Scanner(System.in); // do-while loop that asks the user to enter two numbers. // Calculate the sum and display the result. Loop repeats the user wish to perform the operation again. do { // Prompt and read the input from the user System.out.print("Enter first number: "); number1 = scn.nextInt(); System.out.print("Enter second number: "); number2 = scn.nextInt(); // Calculate the sum and display the result System.out.print("The sum of the two numbers is : " + ( number1 + number2)); //Prompt and read the input from the user for repeated operations System.out.print("\n\nDo you wish to do this again? (Y/N) "); choice = scn.next().toUpperCase().charAt(0); } while (choice == 'Y' ); } }

In this lab, you will be editing a customer ordering program. It creates a pizza ordered to the specifications that the user desires. It walks the user through ordering, giving the user choices, which the program then uses to decide how to make the pizza and how much the cost of the pizza will be. The user will also receive a $2.00 discount if his or her name is Mike or Diane. You need to apply the following FOUR TASKS to complete and correct this program. TASK #1: The if Statement, Comparing Strings, and Flags Construct a simple if statement. The condition will compare the String input by the user as his or her first name with the first names of the owners, Mike and Diane. Be sure that the comparison is not case sensitive. If the user has either first name, set the discount flag to true. TASK #2: The if-else-if Statement Write an if-else-if statement that lets the computer choose which statements to execute by the user input size (10, 12, 14, or 16). For each option, the cost needs to be set to the appropriate amount. The default else of the above if-else-if statement should print a statement that the user input was not one of the choices, so a 12 inch pizza will be made. It should also set the pizza size to 12 and the cost to 12.99. Compile, debug, and run. You should now be able to get correct output for the pizza size and price . Run your program multiple times ordering a 10, 12, 14, 16, and 17 inch pizza. TASK #3: The switch Statement Write a switch statement that compares the user's choice with the appropriate characters (make sure that both capital letters and small letters will work). Each case will assign the appropriate string indicating crust type to the crust variable. The default case will print a statement that the user input was not one of the choices, so a Hand-tossed crust will be made. Compile, debug, and run. You should now be able to get crust types other than Hand-tossed. Run your program multiple times to make sure all cases of the switch statement operate correctly. TASK #4: Using a Flag as a Condition Write an if statement that uses the flag as the condition. Remember that the flag is a Boolean variable, therefore is true or false. It does not have to be compared to anything. The body of the if statement should contain two statements: A statement that prints a message indicating that the user is eligible for a$2.00 discount. A statement that reduces the variable cost by 2.

import java.util.Scanner; public class CustomerOrder { public static void main(String[] args) { // Create a Scanner object to read input. Scanner keyboard = new Scanner (System.in); String firstName; // User's first name boolean discount = false; // Flag for discount int inches; // Size of the pizza char crustType; // For type of crust String crust = "Hand-tossed"; // Name of crust double cost = 12.99; // Cost of the pizza final double TAX_RATE = .08; // Sales tax rate double tax; // Amount of tax char choice; // User's choice String input; // User input String toppings = "Cheese "; // List of toppings int numberOfToppings = 0; // Number of toppings // Prompt user and get first name. System.out.println("Welcome to Mike and " + "Diane's Pizza"); System.out.print("Enter your first name: "); firstName = keyboard.nextLine(); // Determine if user is eligible for discount by // having the same first name as one of the owners. if ( (firstName.equalsIgnoreCase("Mike")) || firstName.equalsIgnoreCase("Diane")) { discount = true; //True qualifies customer for discount } // Prompt user and get pizza size choice. System.out.println("Pizza Size (inches) Cost"); System.out.println(" 10 $10.99"); System.out.println(" 12 $12.99"); System.out.println(" 14 $14.99"); System.out.println(" 16 $16.99"); System.out.println("What size pizza " + "would you like?"); System.out.print("10, 12, 14, or 16 " + "(enter the number only): "); //Set pizza price per pizza size inches = keyboard.nextInt(); if (inches == 10) { cost = 10.99; } else if (inches == 12) { cost = 12.99; } else if (inches == 14) { cost = 14.99; } else if (inches == 16) { cost = 16.99; } else if (inches != 10 && inches != 12 && inches != 14 && inches != 16) { System.out.println("The number you have entered is not valid; pizza size will be set to 12 inches. "); cost = 12.99; } // Consume the remaining newline character. keyboard.nextLine(); // Prompt user and get crust choice. System.out.println("What type of crust " + "do you want? "); System.out.print("(H)Hand-tossed, " + "(T) Thin-crust, or " + "(D) Deep-dish " + "(enter H, T, or D): "); input = keyboard.nextLine(); crustType = input.charAt(0); // Set user's crust choice on pizza ordered. switch (crustType) { case 'H': case 'h': crust = "Hand-tossed"; break; case 'D': case 'd': crust = "Deep-dish"; break; case 'T': case 't': crust = "Thin-crust"; break; default: System.out.println("User input is not a valid choice; Hand-tossed crust will be made. "); } { // Prompt user and get topping choices one at a time. System.out.println("All pizzas come with cheese."); System.out.println("Additional toppings are " + "$1.25 each, choose from:"); System.out.println("Pepperoni, Sausage, " + "Onion, Mushroom"); } // If topping is desired, // add to topping list and number of toppings System.out.print("Do you want Pepperoni? (Y/N): "); input = keyboard.nextLine(); choice = input.charAt(0); if (choice == 'Y' || choice == 'y') { numberOfToppings += 1; toppings = toppings + "Pepperoni "; } System.out.print("Do you want Sausage? (Y/N): "); input = keyboard.nextLine(); choice = input.charAt(0); if (choice == 'Y' || choice == 'y') { numberOfToppings += 1; toppings = toppings + "Sausage "; } System.out.print("Do you want Onion? (Y/N): "); input = keyboard.nextLine(); choice = input.charAt(0); if (choice == 'Y' || choice == 'y') { numberOfToppings += 1; toppings = toppings + "Onion "; } System.out.print("Do you want Mushroom? (Y/N): "); input = keyboard.nextLine(); choice = input.charAt(0); if (choice == 'Y' || choice == 'y') { numberOfToppings += 1; toppings = toppings + "Mushroom "; } // Add additional toppings cost to cost of pizza. cost = cost + (1.25 * numberOfToppings); // Display order confirmation. System.out.println(); System.out.println("Your order is as follows: "); System.out.println(inches + " inch pizza"); System.out.println(crust + " crust"); System.out.println(toppings); // Apply discount if user is eligible. if (discount == true) { System.out.println("Hooray! You qualify for a $2.00 discount!"); cost -= 2; //Amount discounted from price } // ALL MONEY OUTPUT APPEARS WITH 2 DECIMAL PLACES System.out.printf("The cost of your order " + "is: $%.2f\n", cost); // Calculate and display tax and total cost. tax = cost * TAX_RATE; System.out.printf("The tax is: $%.2f\n", tax); System.out.printf("The total due is: $%.2f\n", (tax + cost)); System.out.println("Your order will be ready " + "for pickup in 30 minutes."); } }

If a real estate agent charges 4% commission and you just bought a house with this agent for 800. thousand dollars. Write a program to calculate and print how much the real estate agent payment. Use 0.04 to represent 4%.

int housePrice = 800000;double commission = 0.04;double agentPayment;agentPayment = housePrice * commission;System.out.print(agentPayment);Output: 32000.0

Convert the following pseudocode to Java code. Be sure to declare the appropriate variables. Store 20 in the speed variable. Store 10 in the time variable. Multiply speed by time and store the result in the distance variable. Display the contents of the distance variable.

int speed, time, distance; speed = 20; time = 10; distance = speed * time; System.out.print(distance); Output: 200

To compile a program named First you would use which of the following commands?

javac First.java

What output will be produced by the following code? int extra = 2; if (extra < 0) System.out.println("small");else if (extra == 0) System.out.println("medium");else System.out.println("large")

large

The following data: 72 'A' "Hello World" 2.8712

literals

In general, _________ errors are hard to find and can be very challenging.

logic (or logical)

What is the name of the variable that controls the number of iteration that is performed by a loop.

loop control variable

Suppose n1 and n2 are two int variables that have been given values. Write a Boolean expression that returns true if the value of n1 is greater than or equal to the value of n2 ; otherwise, it should return false.

n1 >= n2

Which Java keyword is used to create an instance of a class.

new

Does the following sequence produce a division by zero? int j = -1; if ((j > 0) && (1/(j+1) > 10)) System.out.println(i);

no

The while loop is this type of loop.

pretest

In Java every complete statement ends with a

semicolon

What output will be produced by the following code? int extra = -37; if (extra < 0) System.out.println("small"); else if (extra == 0) System.out.println("medium");else System.out.println("large")

small

The Scanner.nextLine method returns a _________ data type.

string

A boolean type variable can store a true or false value.

true

The Boolean operators &&, ||, !, and ^ operate with Boolean values and variables.

true

The keyword break is optional in a switch statement, but it is normally used at the end of each case in order to skip the remainder of the switch statement. If the break statement is not present, the next case statement will be executed.

true

The switch statement makes control decisions based on a switch expression of typechar, byte, short, int, or String.

true

Determine if the value is true of each of the following Boolean expressions,assuming that the value of the variable count is 0 and the value of the variable limit is 10. 1. (count == 0) && (limit < 20) 2. count == 0 && limit < 20 3. (limit > 20) || (count < 5) 4. (count == 1) && (x < y)

true true true

Which loop is considered to be a pretest loop?

while loop

The following statement should determine whether count is outside the range of 0 through 100. What relational operation should be used? if (count < 0 ___ count > 100)

||