Expressions

For exercises 1 to 14, indicate the order in which the expressions will be evaluated by putting sequence numbers (1, 2, etc.) below each operator in the expression. Refer to Java operator precedence.

1. a – b – c – d 8. a – (b – c) – d

2. a – b + c – d 9. (a – (b – c)) – d

3. a + b / c / d 10. a – ((b – c ) – d)

4. a + b / c * d 11. a % (b % c) * d * e

5. a / b * c * d 12. a + (b – c ) * d – e

6. a % b / c * d 13. (a + b) * c + d * e

7. a % b % c % d 14. (a + b) * (c / d) % e

For exercises 15 to 57, consider the declarations below, then indicate the value that is assigned in each assignment statement. That is, show what is stored in the iResult, fResult, or sResult variables after each assignment. Show each floating point value to three places past the decimal point.

int iResult, num1 = 25, num2 = 40, num3 = 17, num4 = 5;

int num5 = -14, num6 = -27;

double fResult, val1 = 17.0, val2 = 12.78;

String sResult, title = "Java Software Solutions";

15. iResult = num1 / num4;

16. fResult = num1 / num4;

17. iResult = num3 / num4;

18. fResult = num3 / num4;

19. fResult = val1 / num4;

20. fResult = val1 / val2;

21. iResult = num1 / num2;

22. fResult = num1 / num2;

23. fResult = (double) num1 / num2;

24. fResult = num1 / (double) num2;

25. fResult = (double) (num1 / num2);

26. iResult = (int) (val1 / num4);

27. fResult = (int) (val1 / num4);

28. fResult = (int) ((double) num1 / num2);

29. iResult = num3 % num4;

30. iResult = num2 % num3;

31. iResult = num3 % num2;

32. iResult = num2 % num4;

33. iResult = num5 % num4;

34. iResult = num6 % num5;

35. iResult = title.length();

36. fResult = title.length();

37. iResult = title.indexOf('t');

38. iResult = title.indexOf('q');

39. iResult = title.lastIndexOf('a');

40. sResult = title.toUpperCase();

41. sResult = title.replace('o', 'X');

42. sResult = title.substring(8);

43. sResult = title.substring(8, 16);

44. iResult = (title.substring(8, 16)).length();

45. sResult = title + num1;

46. sResult = title + num1 + num2;

47. sResult = title + (num1 + num2);

48. iResult = Math.abs(num6);

49. iResult = Math.abs(num1 – num2);

50. fResult = Math.sqrt(num2);

51. fResult = Math.pow(num4, 3);

52. iResult = Math.max(num2, num3);

53. iResult = Math.floor(val2);

54. iResult = Math.ceil(val2);

55. fResult = Math.sin(num2 + num1 * 2);

56. fResult = Math.PI * num4;

57. fResult = Math.pow(title.length(), 2) + num3 *

Math.sqrt(num3 / num4);

Conditionals

For exercises 1 to 27, indicate the output that will be produced. Assume the following declarations:

final int MAX = 25, LIMIT = 100;

int num1 = 12, num2 = 25, num3 = 87;

1. if (num1 < MAX)

System.out.println ("apple");

2. if (num2 <= MAX)

System.out.println ("apple");

System.out.println ("orange");

3. if (MAX > num3)

System.out.println ("apple");

System.out.println ("orange");

4. if (num3 >= LIMIT)

System.out.println ("apple");

System.out.println ("orange");

System.out.println ("pear");

5. if (num2 == MAX)

{

System.out.println ("apple");

System.out.println ("orange");

}

System.out.println ("pear");

6. if (num3-num2 > 2*MAX)

System.out.println ("apple");

else

System.out.println ("orange");

7. if (LIMIT+num3 <= 150)

{

System.out.println ("apple");

System.out.println ("orange");

}

else

System.out.println ("pear");

8. if (2*num1 != num2)

System.out.println ("apple");

else

{

System.out.println ("orange");

System.out.println ("pear");

}

9. if (LIMIT%num1 + 4 == num1 + (MAX-num2))

{

System.out.println ("apple");

System.out.println ("orange");

}

else

{

System.out.println ("pear");

System.out.println ("banana");

}

10. if (num1 < MAX)

if (LIMIT >= num2)

System.out.println ("apple");

System.out.println ("orange");

11. if (LIMIT <= LIMIT)

if (num3 == num1)

System.out.println ("apple");

System.out.println ("orange");

12. if (num2 > 18)

if (num1 < 0)

System.out.println ("apple");

else

System.out.println ("orange");

System.out.println ("pear");

13. if (LIMIT >= 4*num2)

if (MAX == 25)

System.out.println ("apple");

else

System.out.println ("orange");

else

System.out.println ("pear");

14. if (num2 < num1)

if (num3 < LIMIT)

System.out.println ("apple");

else

System.out.println ("orange");

System.out.println ("pear");

15. if (num3 == 87)

{

if (num2 != MAX)

System.out.println ("apple");

}

else

System.out.println ("orange");

System.out.println ("pear");

16. if (num1+num2 > num3)

System.out.println ("apple");

else

if (num2*LIMIT != 3298)

System.out.println ("orange");

17. if (LIMIT%MAX == 3)

System.out.println ("apple");

else

if (num2 == MAX)

System.out.println ("orange");

else

System.out.println ("pear");

18. if (num3 >= MAX)

{

if (MAX/num2 == 1)

System.out.println ("apple");

System.out.println ("orange");

if (LIMIT-num3 > num1+2)

System.out.println ("pear");

else

{

System.out.println ("banana");

System.out.println ("kiwi");

}

else

if (num2*2 == MAX*2)

System.out.println ("grapefruit");

else

System.out.println ("lime");

System.out.println ("coconut");

19. if (num2 > num1 && LIMIT != 100)

System.out.println ("apple");

System.out.println ("orange");

20. if (num3 == num2 && MAX > 50)

System.out.println ("apple");

System.out.println ("orange");

21. if (num1 > 7 && LIMIT <= 100)

System.out.println ("apple");

System.out.println ("orange");

22. if (num3 < 40 || num3 > 50)

System.out.println ("apple");

System.out.println ("orange");

23. if (MAX == LIMIT || num1*2 == num2)

System.out.println ("apple");

System.out.println ("orange");

24. if (num2%2 != 0 || num3 > LIMIT)

System.out.println ("apple");

System.out.println ("orange");

25. if (MAX == 25 && num2 != MAX || num1 < num3)

System.out.println ("apple");

System.out.println ("orange");

26. if (num3 == 87 || num2 > num1 && MAX > LIMIT)

System.out.println ("apple");

System.out.println ("orange");

27. if ((num3 == 87 || num2 > num1) && MAX > LIMIT)

System.out.println ("apple");

System.out.println ("orange");

For exercises 28 to 41, write code segments that will perform the specified action. Assume that all variables have already been declared and given values.

28. Print "Hurrah!" if sum is evenly divisible by count.

29. Increment the integer variable total if total is zero and decrement total otherwise.

30. Print "num is zero", "num is negative", or "num is positive" as appropriate based on the current value of num.

31. Print "num is zero", "num is even", or "num is odd" as appropriate based on the current value of num.

32. Print "Victory" only if result is greater than or equal to 500 and penalty is equal to zero (use nested ifs).

33. Print "Victory" only if result is greater than or equal to 500 and penalty is equal to zero (use logical operators).

34. Assign the smallest of two integer values num1 and num2 to the variable smallest. (use an if-else statement)

35. Assign the smallest of two integer values num1 and num2 to the variable smallest. (use the conditional operator)

36. Assign the smallest of three integer values num1, num2, and num3 to the variable smallest. (do not use logical operators)

37. Assign the smallest of three integer values num1, num2, and num3 to the variable smallest. (use logical operators)

38. Print "This character is a vowel." if the character stored in the variable letter is a lowercase vowel.

39. Of the two characters stored in the variables ch1 and ch2, print the one which comes later in the Unicode character set.

40. Print "Uppercase", "Lowercase", or "Not a letter" depending on whether the character stored in ch is an uppercase alphabetic character, a lowercase alphabetic character, or not an alphabetic character at all.

41. Print "Equal" if two floating point values stored in val1 and val2 are exactly equal, "Essentially Equal" if they are within 0.0001 of each other, or "Not Equal" otherwise.

Loops

For exercises 1 to 15, indicate the output that will be produced. Assume the following declarations are made just before each exercise. That is, assume these initializations are in effect at the beginning of each problem:

final int MIN = 10, MAX = 20;

int num = 15;

1. while (num < MAX)

{

System.out.println (num);

num = num + 1;

}

2. while (num < MAX)

{

num = num + 1;

System.out.println (num);

}

3. do

{

num = num + 1;

System.out.println (num);

}

while (num <= MAX);

4. while (num < MAX)

{

System.out.println (num);

num = num - 1;

}

5. while (num > MIN)

{

System.out.println (num);

num = num - 1;

}

6. while (num < MAX)

{

System.out.println (num);

num += 2;

}

7. while (num < MAX)

{

if (num%2 == 0)

System.out.println (num);

num++;

}

8. do

{

num = num + 1;

if (num*2 > MAX+num)

System.out.println (num);

}

while (num <= MAX);

9. for (int value=0; value >= 7; value++)

System.out.println (value);

10. for (int value=7; value < 0; value--)

System.out.println (value);

11. for (int value=1; value >= 20; value+=4)

System.out.println (value);

12. for (int value=num; value <= MAX; value++)

System.out.println (value);

13. for (int value=num; value <= MAX; value++)

if (value%4 != 0)

System.out.println (value);

14. for (int count1=1; count1 <= 7; count1++)

{

for (int count2=1; count2 <= 5; count2++)

System.out.print ("#");

System.out.println();

}

15. for (int count1=1; count1 <= 5; count1++)

{

for (int count2=1; count2 <= 5; count2++)

System.out.print (count1*count2 + " ");

System.out.println();

}

For exercises 16 to 29, write code segments that will perform the specified action.

16. Verify that the user enters a positive value. (use a while loop)

17. Verify that the user enters an even value (use a do loop)

18. Read and print values entered by a user until a particular sentinel value is encountered. Do not print the sentinel value. Assume the sentinel value is stored in a constant called SENTINEL.

19. Read values from the user, quitting when a sentinel value of 0 is entered. Compute and print the product of all values entered (excluding the sentinel value).

20. Print the odd numbers between 1 and 100.

21. Print the multiples of 3 from 300 down to 3.

22. Print the numbers between LOW and HIGH that are evenly divisible by four but not by five.

23. Print all of the factors of a value stored in the variable number. Assume the value is positive.

24. Read 10 values from the user and print the lowest and highest value entered.

25. Determine and print the number of times the character 'a' appears in the String variable str.

26. Print the characters stored in the String variable str backwards.

27. Print every other character in the String variable str starting with the first character.

28. Print a sequence of asterisk characters in the following configuration, continuing for LINES number of asterisks.

29. Print the characters of a String variable str in a diagonal line downward. For example, if str contained "Compile", the output would be:

Writing Methods

For each exercise below, write the method described. Give all of the methods public visibility. Assume all ranges are inclusive (include both end points).

1. Write a method called powersOfTwo that prints the first 10 powers of 2 (starting with 2). The method takes no parameters and doesn't return anything.

2. Write a method called alarm that prints the word "Alarm!" multiple times on separate lines. The method should accept an integer parameter that specifies how many times the output line is printed.

3. Write a method called sum100 that returns the sum of the integers from 1 to 100.

4. Write a method called sumRange that accepts two integer parameters that represent a range. You may assume the first parameter is less than or equal to the second. The method should return the sum of the integers in that range.

5. Write a method called maxOfTwo that accepts two integer parameters and returns the larger of the two.

6. Write a method called larger that accepts two floating point parameters (of type double) and returns true if the first parameter is greater than the second, and false otherwise.

7. Write a method called countA that accepts a String parameter and returns the number of times the letter ‘A’ is found in the string.

8. Write a method called evenlyDivisible that accepts two integer parameters and returns true if the first parameter is evenly divisible by the second, or vise versa, and false otherwise. You may assume that neither parameter is zero.

9. Write a method called average that accepts three integer parameters and returns their average as a floating point value.

10. Overload the average method of the previous exercise such that if four integers are provided as parameters, the method returns the average of all four.

11. Overload the average method once more to accept five integer parameters and return their average.

12. Write a method called multiConcat that takes a String and an integer as parameters, and returns a String that is the parameter string concatenated with itself n number of times (where n is the second parameter). For example, if the parameters are "hi" and 4, the return value is "hihihihi".

13. Overload the multiConcat method from the previous example such that if the integer parameter is not provided, the method returns the string concatenated with itself. For example, if the parameter is "test" the return value is "testtest".

14. Write a method called isAlpha that accepts a character parameter and returns true if that character is either an uppercase or lowercase alphabetic letter.

15. Write a method called validate that accepts three integer parameters. The first two parameters represent a range, and the purpose of the method is to verify that the value of the third parameter is in that range. You may assume that the first parameter is less than or equal to the second. If the third parameter is not in the specified range, the method should prompt the user and read a new value. This new value should be tested for validity as well. The method should only return to the calling method once a valid value has been obtained, and it should return the valid value.

16. Write a method called floatEquals that accepts three floating point values as parameters. The method should return true if the first two parameters are essentially equal, within the tolerance of the third parameter.

17. Write a method called reverse that accepts a String as a parameter and returns a String that contains the characters of the parameter in reverse order. Note: there is actually a method in the String class that performs this operation, but for the sake of this exercise you will write your own.

18. Write a method called isIsoceles that accepts three integer parameters that represent the lengths of the sides of a triangle. The method should return true if the triangle is isosceles but not equilateral, meaning that exactly two of the sides have an equal length, and false otherwise.

19. Write a method called randomInRange that accepts two integer parameters representing a range. You may assume that the first parameter is less than or equal to the second, and that both are positive. The method should return a random integer in the specified range.

20. Overload the randomInRange method of the previous exercise such that if only one parameter is provided, the range is assumed to be from 1 to that value. You may assume the parameter value is positive.

Classes

1. What is the difference between an object and a class?

Explian the difference between actual parameter and a formal parameter.

How are overloaded methods distinguished from each other.

Write a class called Die that has six sided face, has a variable called face. Include methods called rollDice, which picks a random number to set the face of the die. Write getFace method also.

Write a class called Pairof Dice composed of two six sided Die objects. Create a driver class with main method that rolls pairofDice object multiple times, counting the number of boxcars (two sixes) that occur.

Write a class called Card that represents the standard playing card. Each card has a suit and a face value. Create a program that deals 50 playing cards.

Write the Coin class that has face whose value is HEAD or TAIL. Write a constructor that initialiazes the face to HEAD. Now write methods to flip the coin which picks a random number to assign to the face. and getface. Write a driver program in the main that flips the coin 50 times and returns the number of heads found.

Write a Student class that contains gpa, name, and id. Write get and set methods for each variable. Write printInfo that prints the student info. Write a driver program that reads the student info from the standard input and creates Student object.

Write an account class that has name, balance account number and a constant called MINIMUM_BALANCE of $100. Write methods to withdraw and deposit. Constructor initializes the balance. Withdrawl is not successful if the balance goes below minimum balance.

Write a class called Clock wich has hour, min and seconds. Write a method called tick which increases time by 1 sec. Write a method to display the time. Write a driver program that creates a clock with 6:59:50 and prints time after 50 ticks.

ARRAYS

Which of the following are valid array declarations?

Int primes = {2,3,4,5,7,9}

Float elapsedTimes[] = {11.47,12.04,11.72,13.88}

Int[ ] scores = int [30];

Int[] scores = new int[30];

Int[] primes = new {2,5,7,9};

Describe five problems that are difficult to implement without arrays.
Write a program that reads an arbitrary number of doubles with at most 100 and prints the one that repeats most number of times.
Show the execution of bubble sort on the following array:

45 23 25 7 67 90 100 26