first sample test
1) b
2) b
3) d
4) c
5) not necessary, but (a)
6) c
7) d
8) d
9) B
10) b
11) wasn't covered, but it is called a recursive function
12) d
13) True
14) d
15) b
16) c
Debugging:
1) a logic error. shouldv'e used ReDim Preserve
2) a logic error. you can't swap if these are passed byval. change to byref
3) syntax error. should be Next, rather than End For
Programming:
1) skip this. it won't be this high-level.
2)
For I = 1 to 10
Debug.Print(I^3)
Next
3) don't worry about it. but it would be a nested loop.
CS80 Fall 2010 Semester
Tuesday, December 14, 2010
Monday, December 13, 2010
Final review
general format:
60 points of m/ch and short answer
40 points of programming (choose 4 of 5)
20 points of tracing
Tracing example:
from 6.1, q 5
focus on arrays and loops
a LITTLE on functions and subs
general knowledge from previous sections
review of second practice exam
m/ch:
1) c
2) c
3) b
4) b
5) a
6) d
2D arrays
Dim myVar(8, 8) As Double
81 slots
7.5 two dimensional arrays
7) a
8) c
9) c
10) c
11) c
12) a
Part III
1) Write a SubRoutine called NumbersInSequence that takes two integer parameters, I and J, and prints out all the numbers from I to J.
Sub NumbersInSequence(ByVal I as Integer, ByVal J as Integer)
For K = I to J
ListBox1.Items.Add(K)
Next
End Sub
2)
Sub PrintUntilSeven(ByVal x() as Integer)
For i = 0 to UBound(x)
Debug.Print(x(i))
If x(i) = 7 Then
Exit For
Endif
Next
End Sub
Sub PrintUntilSeven(ByVal x() as Integer)
For each t in x
Debug.Print(t)
If t = 7 Then
Exit For
Endif
Next
End Sub
Sub PrintUntilSeven(ByVal x() as Integer)
i = 0
Do While x(i) <> 7
Debug.Print(x(i))
Loop
End Sub
Select Case letter
Case "A"
Debug.Print("Apple")
Case "B"
Debug.Print("Banana")
Case "C"
Debug.Print("Cookie")
Case "D"
Debug.Print("Deer")
End Select
60 points of m/ch and short answer
40 points of programming (choose 4 of 5)
20 points of tracing
Tracing example:
from 6.1, q 5
focus on arrays and loops
a LITTLE on functions and subs
general knowledge from previous sections
review of second practice exam
m/ch:
1) c
2) c
3) b
4) b
5) a
6) d
2D arrays
Dim myVar(8, 8) As Double
81 slots
7.5 two dimensional arrays
7) a
8) c
9) c
10) c
11) c
12) a
Part III
1) Write a SubRoutine called NumbersInSequence that takes two integer parameters, I and J, and prints out all the numbers from I to J.
Sub NumbersInSequence(ByVal I as Integer, ByVal J as Integer)
For K = I to J
ListBox1.Items.Add(K)
Next
End Sub
2)
Sub PrintUntilSeven(ByVal x() as Integer)
For i = 0 to UBound(x)
Debug.Print(x(i))
If x(i) = 7 Then
Exit For
Endif
Next
End Sub
Sub PrintUntilSeven(ByVal x() as Integer)
For each t in x
Debug.Print(t)
If t = 7 Then
Exit For
Endif
Next
End Sub
Sub PrintUntilSeven(ByVal x() as Integer)
i = 0
Do While x(i) <> 7
Debug.Print(x(i))
Loop
End Sub
Select Case letter
Case "A"
Debug.Print("Apple")
Case "B"
Debug.Print("Banana")
Case "C"
Debug.Print("Cookie")
Case "D"
Debug.Print("Deer")
End Select
Wednesday, December 8, 2010
lecture notes
sorted array
linear search - can speed up; we can end prematurely
binary search
search algorithm
why "Or n = 9"?
do not want OutOfArrayBounds exception
Dim name2Find As String
Dim n As Integer = -1
name2Find = txtName.Text.ToUpper
' start as pessimist
txtResult.Text = "Not found."
' for i = 0 to 9
' if nom(i) = name2Find then...
' next
For Each x in nom
if x = name2Find Then
txtResult.Text = "Found."
Elseif x = name2Find Then
exit for
Endif
Next
' that was my version of linear search as found in book
Dim list1() As String = {"Al", "Carl", "Don", "Greg", "Jack"}
Dim list2() As String = {"Bob", "Carl", "Eric", "Greg", "Herb"}
to merge, I COULD first copy contents of both, and then sort
Bad idea!
do while ia <= Ubound(a) and ib <= Ubound(B)
if A(ia) <= B(ib) Then
C(ic) = A(ia)
ia+= 1
else
C(ic) = B(ib)
ib +=1
endif
ic +=1
loop
for ia = ia to Ubound(A)
C(ic) = A(ia)
ic += 1
next
for ib = ib to Ubound(B)
C(ic) = A(ib)
ic += 1
next
linear search - can speed up; we can end prematurely
binary search
search algorithm
why "Or n = 9"?
do not want OutOfArrayBounds exception
Dim name2Find As String
Dim n As Integer = -1
name2Find = txtName.Text.ToUpper
' start as pessimist
txtResult.Text = "Not found."
' for i = 0 to 9
' if nom(i) = name2Find then...
' next
For Each x in nom
if x = name2Find Then
txtResult.Text = "Found."
Elseif x = name2Find Then
exit for
Endif
Next
' that was my version of linear search as found in book
Dim list1() As String = {"Al", "Carl", "Don", "Greg", "Jack"}
Dim list2() As String = {"Bob", "Carl", "Eric", "Greg", "Herb"}
to merge, I COULD first copy contents of both, and then sort
Bad idea!
do while ia <= Ubound(a) and ib <= Ubound(B)
if A(ia) <= B(ib) Then
C(ic) = A(ia)
ia+= 1
else
C(ic) = B(ib)
ib +=1
endif
ic +=1
loop
for ia = ia to Ubound(A)
C(ic) = A(ia)
ic += 1
next
for ib = ib to Ubound(B)
C(ic) = A(ib)
ic += 1
next
Some sample exams
Monday, December 6, 2010
last time: redim
resize an array
using a for each loop
For Each letter in sentence.ToCharArray()
If (letter >= "A") And (letter <= "Z") Then
index = Asc(letter) - 65 'The ANSI value of "A"is 65
charCount(index) += 1
End If
Next
how freq table might be useful
huffman trees
http://en.wikipedia.org/wiki/Huffman_coding
AN example of using freq tables
"If arrayOne() and arrayTwo() have been declared with the same data type, then the statement
arrayOne = arrayTwo
makes arrayOne() an exact duplicate of arrayTwo(). It will have the same size and contain the same information.
"
This comment is false. fixed in later versions of the book
so, how DO we copy an array?
two ways:
1)
Dim a(4) As Integer = {6, 8, 2, -8, 0}
Dim b() as Integer
' i want to make b an exact duplicate of a
ReDim b(UBound(a))
For I = 0 to UBound(a)
b(i) = a(i)
Next
2)
b = a.Clone()
HW: arrays, creating and accessing
q 28, 32
resize an array
using a for each loop
For Each letter in sentence.ToCharArray()
If (letter >= "A") And (letter <= "Z") Then
index = Asc(letter) - 65 'The ANSI value of "A"is 65
charCount(index) += 1
End If
Next
how freq table might be useful
huffman trees
http://en.wikipedia.org/wiki/Huffman_coding
AN example of using freq tables
"If arrayOne() and arrayTwo() have been declared with the same data type, then the statement
arrayOne = arrayTwo
makes arrayOne() an exact duplicate of arrayTwo(). It will have the same size and contain the same information.
"
This comment is false. fixed in later versions of the book
so, how DO we copy an array?
two ways:
1)
Dim a(4) As Integer = {6, 8, 2, -8, 0}
Dim b() as Integer
' i want to make b an exact duplicate of a
ReDim b(UBound(a))
For I = 0 to UBound(a)
b(i) = a(i)
Next
2)
b = a.Clone()
HW: arrays, creating and accessing
q 28, 32
Wednesday, December 1, 2010
Array
a collection
the "problem" with dealing with a collection as a bunch of separate variables.
1) unweildy
2) not easily changable to diff number of variable
Dim score(29) As Double
Dim student(29) As String
score(0) = 87
score(1) = 92
If you write programs involving large arrays
a good idea is to test using small arrays first
For i As Integer = 0 To 29
lstBox.Items.Add(score(i))
Next
a new loop!
For Each x in score
lstBox.Items.Add(x)
Next
we can make the array a class-level variable
and fill it in the Form_Load event
Dim teamName(3) As String = {"Packers", "Packers", "Jets", "Chiefs"}
often, we will use loops to iterate thru an array.
easier way: use for each loop
harder way: for i = 0 to whatever the upper bound is
problem: 29 is a "magic number". makes code hard to read. introduces errors. let us say i change to 60 students!
for i = 0 to UBound(scores)
scores(i) = 90
next
for i = 0 to scores.GetUpperBound(0)
scores(i) = 90
next
Dim scores() As Double
realize that scores, or any array, is a reference type
ReDim scores(29)
ReDim scores(n)
dynamic memory allocation
Dim scores(3) As Integer
scores(0) = 58
scores(1) = 78
scores(2) = 100
scores(3) = 98
ReDim scores(4)
' alternatively
ReDim Preserve scores(4)
will preserve the values
a collection
the "problem" with dealing with a collection as a bunch of separate variables.
1) unweildy
2) not easily changable to diff number of variable
Dim score(29) As Double
Dim student(29) As String
score(0) = 87
score(1) = 92
If you write programs involving large arrays
a good idea is to test using small arrays first
For i As Integer = 0 To 29
lstBox.Items.Add(score(i))
Next
a new loop!
For Each x in score
lstBox.Items.Add(x)
Next
we can make the array a class-level variable
and fill it in the Form_Load event
Dim teamName(3) As String = {"Packers", "Packers", "Jets", "Chiefs"}
often, we will use loops to iterate thru an array.
easier way: use for each loop
harder way: for i = 0 to whatever the upper bound is
problem: 29 is a "magic number". makes code hard to read. introduces errors. let us say i change to 60 students!
for i = 0 to UBound(scores)
scores(i) = 90
next
for i = 0 to scores.GetUpperBound(0)
scores(i) = 90
next
Dim scores() As Double
realize that scores, or any array, is a reference type
ReDim scores(29)
ReDim scores(n)
dynamic memory allocation
Dim scores(3) As Integer
scores(0) = 58
scores(1) = 78
scores(2) = 100
scores(3) = 98
ReDim scores(4)
' alternatively
ReDim Preserve scores(4)
will preserve the values
Monday, November 29, 2010
lecture notes
For Loops
are an example of syntactic sugar
1) how do i start?
2) how do i end?
3) step
For i = 1 to 10
ListBox1.Items.Add(i*i)
Next
When should I use a For loop?
1) you want to do something a fixed number of times
(In this instance, i don't *use* the variable i inside the loop at all)
2) when you want to generate a series of numbers
ex 1:
Dim year as Integer
pop = 300000
For year = 2006 To 2010
LstTable.Items.Add(year & " " & pop)
pop = pop + pop * 0.03
Next
Alternatively:
pop = 300000
For year as integer = 2006 To 2010
LstTable.Items.Add(year & " " & pop)
pop = pop + pop * 0.03
Next
if I have:
x operator= 6
x = x operator 6
for loops, 30-40 even
row = ""
for i = 1 to 10
row = row & "*"
next
for i = 1 to 10
listbox1.items.add(row)
next
for i = 1 to 10
row = ""
for i = 1 to 10
row = row & "*"
next
listbox1.items.add(row)
next
are an example of syntactic sugar
1) how do i start?
2) how do i end?
3) step
For i = 1 to 10
ListBox1.Items.Add(i*i)
Next
When should I use a For loop?
1) you want to do something a fixed number of times
(In this instance, i don't *use* the variable i inside the loop at all)
2) when you want to generate a series of numbers
ex 1:
Dim year as Integer
pop = 300000
For year = 2006 To 2010
LstTable.Items.Add(year & " " & pop)
pop = pop + pop * 0.03
Next
Alternatively:
pop = 300000
For year as integer = 2006 To 2010
LstTable.Items.Add(year & " " & pop)
pop = pop + pop * 0.03
Next
if I have:
x operator= 6
x = x operator 6
for loops, 30-40 even
row = ""
for i = 1 to 10
row = row & "*"
next
for i = 1 to 10
listbox1.items.add(row)
next
for i = 1 to 10
row = ""
for i = 1 to 10
row = row & "*"
next
listbox1.items.add(row)
next
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