Extended Prelude to Programming

Third Edition

Answers to Even-numbered Review Exercises

Chapter 0

2. / ENIAC / 20. / d
4. / minicomputer / 22. / a
6. / Web pages / 24. / a
8. / motherboard / 26. / b
10. / 1024 or 102 / 28. / c
12. / DVD / 30. / False
14. / laser / 32. / False
16. / operating system / 34. / True
18. / FORTRAN / 36. / False
20. / b / 38. / c, b, a, d

Chapter 1

2. / program development cycle
4. / data
6. / Weight
8. / declared
10. / character
12. / b
14. / True
16. / True
18. / True
20. / (a) 4 (b) 100
22. / (a) 4 (b) 0
24. / (a) 234,000
(b) 0.0000234
26. / Write “Enter your age: “
Input Age
28. / Write “Enter your age: “
Input Age
Set New = Age – 5
Write “You don’t look a day over “, New
30. / 1.25 or 1
32. / No
34. / (a) none
(b) Set Number1 = 4
Set Number1 = Number 1 + 1
Set Number2 = 3
Set Number 2 = Number1 * Number2
(c) Write Number 2
36. / Write “Enter a number: ”
Write “Enter another number: “
38. / Write “The result of the computation is: “
40. / Declare Number1 As Integer
Declare Number2 As Integer

Chapter 2

2. / output
4. / call
6. / pseudocode
8. / step
10. / logic
12. / design documentation or trade study documentation
14. / dialog box
16. / object-oriented programming
18. / b
20. / c
22. / c
24. / c
26. / a
28. / True
30. / False
32. / False
34. / False
36. / True
38. / False
40. / True
42. / True
44. / Answers may vary. Some attributes include height, width, color, lock type
Some methods include opening, closing, locking
46.. /
48. / Input Data Module
Write “Enter three numbers: “
Input Number1, Number2, Number3
Calculate Average Module
Set Average = (Number1 + Number2 + Number3) / 3
Output Results Module
Write “The average of the numbers ”
Write “Number1, “, “ , Number2, “and “ Number3
Write “is “, Average
50. / Answers will vary. Some possible sets of test data are:
0, 0, 0 or 2, 6, 985 or -253.45, 987, 0 etc.

Chapter 3

2. / If-Then-Else
4. / d
6. / (a) False (b) False (c) True (d) False
8. / (a) True (b) False (c) False (d) False
10. / False
12. / Bye
14. / Write “Enter a number: “
Input NUM
If Num = 1 Then
Write “Yes”
End If
16. /
18. / Input Num
If Num = 1 Then
Write “Yes”
End If
If Num > 1 Then
Write “No”
End If
20. / = , > , < , <= , > , >=
22. / (a) N <= 0 (b) (N < 0) OR (N > 5)
24. / (a) Input Num
If Num = 1 Then
Write “Yes”
End If
If Num = 2 Then
Write “No”
End If
If Num = 3 Then
Write “Maybe”
End If
(b)  Input Num
If Num = 1 Then
Write “Yes”
Else
If Num = 2 Then
Write “No”
Else
If Num = 3 Then
Write “Maybe”
End If
End If
End If
(c) Input Num
Select Case of Num
Case 1:
Write “Yes”
Case 2:
Write “No”
Case 3:
Write “Maybe”
End Case
26. / multiple alternative structure
28. / Input X
If X > 6 Then
Write “Pass”
Else
If (X = 5) OR (X = 6) Then
Write “Retest”
Else
Write “Fail”
End If
End If
30. / 5
Not
And
32. / (a) 1 (b) 2 (c) 3
Done Done Done
34. / Change the line as follows: If Grade = “A” Then
36. / YES
38. / the Else clause
40. / No

Chapter 4

2 / greater than
4. / validate
6. / (a) True (b) True
8. / (a) False (b) True (c) True
10. / True
12. / False
14. / False
16. / False
18. / 2
1
20. / 2
1
22. /
24. / 3
5
7
26. / Write “Enter a negative number: “
Input NegativeNumber
While NegativeNumber >= 0
Write “Enter a negative number: “
Input NegativeNumber
End While
28. / (a) 1 (b) -1
30. / Write “Enter an integer: “
Input MyInteger
While MyInteger > Int(MyInteger)
Write “Enter an integer: “
Input MyInteger
End While
32. / 16
34. /
36. / Set A = 0
Set Total = 0
For B = 1 Step 1 To N
Set A = A + 2 * B – 1
Set Total = Total + (2 * B – 1)
Set B = B + 1
End For
Write A
Set Average = Total / N
38. / 4
5
8
10
12
15
40. / Hello

Chapter 5

2. / 3
4. / 6
6. / True
8. / False
10. / False
12. / False
14. / True
16. / Declare Numbers[25]
Write “Enter a number. Enter 0 when done.”
Input MyNumber
Set K = 0
While MyNumber > 0
Set Numbers[K] = MyNumber
Set K = K + 1
End While
18. / 4
1 9
20. / Correct the While statement as follows:
While (Found = 0) AND (Index < N)
Also, change Set Found = 0 inside the If-Then clause to:
Set Found = 1
22. / A[K] = 20, A[K + 1] = 10
24. / Change the If-Then statement to:
If A[K] > A[K + 1] Then
and change the Set Flag = 1 inside the If-Then clause to:
Set Flag = 0
26. / Write Name[0], Name[9]
28. / Write Length(FullName)
30. / Set First = FullName[0]
For K = 1 Step 1 To 24
If FullName[K] = “ “ Then
Set Last = FullName[K + 1]
End If
End For
Write First, “.” , Last. “.”
32. / Declare Score1[25], Score2[25], Score3[25] As Real
34. / For K = 0 Step 1 To 24
Write Score1[K], Score2[K], Score3[K]
End For
36. / For K = 0 Step 1 To 4
Set Sum = 0
For J = 0 Step 1 To 4
Set Sum = Sum + X[K, J]
End For(J)
Write Sum
End For(K)
38. / Dewey4
Dewey5

Chapter 6

2. / fields
4. / binary
6. / direct access or random access
8. / control variable
10. / True
12. / False
14. / True
16. / True
18. / True
20. / False
22. / Open “people” For Input As NameFile
While NOT EOF(NameFile)
Read NameFile, PersonName
Write PersonName
End While
Close NameFile
24. / “A”,25<CR>”C”,20<CR>”E”,15<CR<EOF>
26. / “D”,90<CR<EOF>
28. / (a) Character, String (b) Integer, Real
30. / 5
32. / Shirley and Tamara
34. / “Tamara”<CR>”Shirley”<CR>”Sam”<CR>”Michael”<CR>”Marjorie”<CR>”Corinne”<CR<EOF>

Chapter 7

2. / exported
4. / IPO chart
6. / global
8. / built-in
10. / 7
12. / True
14. / 2 * X ( i.e., 2) à assigned to Num1
X (i.e., 1) à assigned to Num2
5 à assigned to Num3
16. / Display:
Input Processing Output
Num1, Num2, Num3 None Num1, Num2, Num3
18. / 2 1 5
20. / Subprogram Flip(X As Refm Y As Ref)
Declare Temp As Real
Set Temp = X
Set X = Y
Set Y = Temp
End Subprogram
22. / local: X in Sub, Num1, Num2
global: X in main, Y
24. / 5
1
4
26. / 5
1
2
28. / (a) 4 (b) 1
30. / (a) “-1.5” (b) 87.6 ,(N=1)
32. / 2
34. / 3
36. / Main
Declare X, Y As Real
Write “Enter a number: “
Input X
Write “Enter another number: “
Input Y
Write Average(X, Y)
End Program
38. / three times
40. / Function Fac(N) As Integer
Set Product = 1
For K = 2 Step 1 To N
Set Product = Product * K
End For
Set Fac = Product
End Function
42. / Function Mult(M, N) As Integer
Set Total = 0
For K = 1 Step 1 To N
Set Total = Total + M
End For
Set Mult = Total
End Function

Chapter 8

2. / object
4. / Public
6. / inheritance
8. / parent (or base), child (or derived)
10. / d
12. / c
14. / b
16. / True
18. / True
20. / False
22. / False
24. / False
26. / False
28. / SetSide, ComputeArea, GetArea, GetSide
30. / Call Square1.SetSide(20)
32. / Write “The area is “ Square1.GetArea
34. / SetSide, GetArea, GetSide, SetHeight, GetHeight, ComputeArea
36. / (a) Text box: Hello
(b) Label objects: The message is:
38. / Date
40. / name, caption or text, enabled
42. / Subprogram OKbutton.Click()
If Option1.Value = True Then
Call Window1.Open
Else
Call Window2.Open
End If
End Subprogram
44. / Subprogram EnterButton.Click()
Set Sum = Val(NumberBox.Text)
Set NumberBox.Text = “ “
End Subprogram

Chapter 9

2. / pseudorandom numbers
4. / Car.Make, Car.Model
6. / indexed
8. / (a) True (b) True
10. / True
12. / True
14. / True
16. / True
18. / False
20. / True
22. / (a) Random(6) (b) Random(2) – 1
24. / For K = 1 Step 1 To 50
Write Random(6)
End For
26. / (a) 33 = “!” (b) 65 = “A” (c) 126 = “~”
28. / (a) “30” (b) “-21.5”
30. / Index = 2
32. / 1
34. / 5
36. / Smith
38. / 25 bytes (characters)
40. / SeekGet DataFile, 1, Car
Write Car.Make, Car.Model
42. / Set Last = LOF(DataFile) / Length(Car)
SeekPut DataFile, Last + 1, Car
44. / SeekGet DataFile, 10, Car
Set Car.Model = “Explorer”
SeekPut DataFile, 10, Car
46. / Set Count = 0
Set Found = 0
While (NOT EOF(IndexFile)) AND (Found = 0)
Read IndexFile, Model
Set Count = Count + 1
If Model = “Camry” Then
Set Car.Make = “ “
Set Car.Model = “ “
SeekPut DataFile, Count, Car
Set Found = 1
End If
End While