4. LOOPING USERFORM CONTROLS
Labels 1,
2 and 3
Public Sub Command_LoopControls_Click()
Label1.Caption = Cells(2, 2).Value
Label2.Caption = Cells(2, 3).Value
Label3.Caption = Cells(2, 4).Value
End Sub
These values are changing
5. LOOPING USERFORM CONTROLS
Public Sub Command_LoopControls_Click()
i=1
i=2
i=3
Label1.Caption = Cells(2, 2).Value
Label2.Caption = Cells(2, 3).Value
Label3.Caption = Cells(2, 4).Value
End Sub
The label is i
The column
is i + 1
10. EXERCISE 1. WRITE A FOR LOOP
Download Lecture 5 Student Example.xlsm
Write a For-Loop for this code in UserForm1.
Remember to declare your counter!
Public Sub LoopExercise1_Click()
Range(“Investment”).Columns(1).Value = TextBox1.Value
Range(“Investment”).Columns(2).Value = TextBox2.Value
Range(“Investment”).Columns(3).Value = TextBox3.Value
End Sub
Questions:
Are the cells being assigned the value of the textboxes?
Or are the textboxes being assigned the values of the cells?
14. NESTED FOR-NEXT LOOP
Repeat this twice
For i = 1 to 3
Cells(i, 1).Value = i
Next i
For k = 1 to 2
For i = 1 to 3
Cells(i, 1).Value = i
Next i
Next k
15. NESTED FOR-NEXT LOOP
Repeat this twice
For i = 1 to 3
Cells(i, 1).Value = i
Next i
For k = 1 to 2
For i = 1 to 3
Cells(i, k).Value = i
Next i
Next k
16. EXERCISE 2. NESTED FOR-NEXT LOOP
Use Lecture 5 Student Example.xlsm
LoopExercise2 in Module1
Write a nested For-Loop for this output.
Remember to declare your counter.
Repeat this twice
17. EXERCISE 2. SOLUTIONS
Cells(1, 1).Value = 1
Cells(1, 2).Value = 2
Cells(1, 3).Value = 3
Cells(2, 1).Value = 1
Cells(2, 2).Value = 2
Cells(2, 3).Value = 3
For i = 1 to 3
Cells(1, i).Value = i
Next i
Repeat this twice
18. EXERCISE 2. SOLUTIONS
Cells(1, 1).Value = 1
Cells(1, 2).Value = 2
Cells(1, 3).Value = 3
Cells(2, 1).Value = 1
Cells(2, 2).Value = 2
Cells(2, 3).Value = 3
For k = 1 to 2
For i = 1 to 3
Cells(1, i).Value = i
Next i
Next k
19. EXERCISE 2. SOLUTIONS
Cells(1, 1).Value = 1
Cells(1, 2).Value = 2
Cells(1, 3).Value = 3
Cells(2, 1).Value = 1
Cells(2, 2).Value = 2
Cells(2, 3).Value = 3
For k = 1 to 2
For i = 1 to 3
Cells(k, i).Value = i
Next i
Next k
20. EXERCISE 3. NESTED FOR-NEXT LOOPS
Use Lecture 5 Student Example.xlsm
LoopExercise3 in Module1
Write a nested For-Loop for this output.
Remember to declare your counter.
Repeat this three times
22. WHAT DOES IT MEAN TO GENERALISE?
Dim i As Integer
For i = 1 to 10
Cells(i +1, 1).Value = i
Next i
I know the number
Dim i As Integer
of TIMEPERIODS
in advance
Const TIMEPERIODS = 10
For i = 1 to TIMEPERIODS
Cells(i +1, 1).Value = i
Next i
23. WHAT DOES IT MEAN TO GENERALISE?
Unknown until the user runs the program
Dim i As Integer
Dim nStocksSelected As Integer
For i = 1 to nStocksSelected
[…..]
Next i
I only want this code to run for the
number of stocks selected by the user
24. WHAT DOES IT MEAN TO GENERALISE?
Replace specific numbers with variables
And assign those variables a value
Enables code to be changed/updated quickly
Only have to change one value instead of every value
Enables you to use user inputs in your loops
You don’t know these in advance
26. ARRAYS
Hold a range (or set) of values
Basically a set of variables
Your arrays will mainly be 1 or 2 dimensions
arrayName(5)
arrayName(5)
arrayName(5, 4)
arrayName is the name of your array
27. ARRAYS
Hold a range (or is onlyvalues 1D Arrays
set) of about
Today
Basically a set of variables
Your arrays will mainly be 1 or 2 dimensions
arrayName(5)
arrayName(5)
arrayName(5, 4)
arrayName is the name of your array
28. DECLARING ARRAYS
The same rules apply to arrays as to variables
Disposable, local or global? – Declare in the right place
Must specify a data type
Also, need to specify the size of the array
The “size” is the number of elements in the array
Public Sub DescriptiveStats()
5 stock prices
Dim stockPrices(5) As Double
Dim stockRet(4) As Double
End Sub
4 stock returns
29. DECLARING ARRAYS
5 stock prices
4 stock returns
The same rules apply to arrays as to variables
Disposable, local or global? – Declare in the right place
Must specify a data type
Also, need to specify the size of the array
The “size” is the number of elements in the array
Public Sub DescriptiveStats()
5 stock prices
Dim stockPrices(5) As Double
Dim stockRet(4) As Double
End Sub
4 stock returns
30. DECLARING ARRAYS
Many times we don’t know the number of
elements that will be in the array.
So, first declare them empty (disposable, local or
global): Dim stockPrices() As Double
For example,
Dim stockRet() As Double
these are local
Public Sub DescriptiveStats()
End Sub
General format
for declaration
arrayName() As DataType
arrayName:= the name of the array
DataType:= Integer, Double, String…
31. DECLARING ARRAYS
After the size of the array is know, re-declare it
inside a procedure
Dim stockPrices() As Double
Dim stockRet() As Double
Dim nDays As Integer
Public Sub DescriptiveStats()
nDays = Combobox1.value
ReDim stockPrices(nDays) As Double
ReDim stockRet(nDays-1) As Double
End Sub
Arrays will most likely
need to be local or
global
User selects number
of days from a
ComboBox on the
userform
Redim both arrays
using the variable
32. DECLARING ARRAYS
After the size of the array is know, re-declare it
inside a procedure
General format for
re-declaration
ReDim arrayName(n) As DataType
n:= the number of elements in the array
33. ARRAYS
VBA counts elements of arrays starting with 0
For example,
This array is named StockPrices
It has 5 elements (i.e., 5 stock prices)
Count
0
1
StockPrices(1)
2
3
StockPrices(2)
StockPrices(3)
4
StockPrices(4)
StockPrices(0)
34. ARRAYS
To force VBA to count from 1
Use Option Base 1 at the top of each module
Count
1
2
StockPrices(2)
3
4
StockPrices(3)
StockPrices(4)
5
StockPrices(5)
StockPrices(1)
35. BEFORE ARRAYS…
We had to declare multiple variables like this:
And assign values like this:
37. FILLING ARRAYS FROM CELLS OR RANGES
A 1D array and a
single For-Next
loop so this is only
for Stock 1
i=1
i=2
i=3
i=4
i=5
.
.
.
i=9
38. FILLING ARRAYS FROM CELLS OR RANGES
Cells(1,1)
i=1
i=2
i=3
i=4
i=5
.
.
.
i=9
A 1D array and a
single For-Next
loop so this is only
for Stock 1
Range Named
“Prices”
39. FILLING ARRAYS IN GENERAL
You can ‘fill’ arrays with values from…
Cells
Ranges
Userform controls
Other variables or arrays
Using equations (e.g., calculate returns)
40. OUTPUTTING ARRAYS TO CELLS OR RANGES
i=1
i=2
i=3
i=4
i=5
**This is assuming we have assigned each element of the array weights() a value**
41. OUTPUTTING ARRAYS TO CELLS OR RANGES
Range Named
“StockWeights”
Cells(1,1)
i=1
i=2
i=3
i=4
i=5
**This is assuming we have assigned each element of the array weights() a value**
42. OUTPUTTING ARRAYS IN GENERAL
You can ‘output’ the value of arrays to…
Cells
Ranges
Userform controls
Other variables or arrays
43. EXERCISE 4A. WRITE A FOR LOOP
Use Lecture 5 Student Example.xlsm
LoopExercise4A in Module1
Declare an array for stock returns
Use that array in a For-Loop to rewrite this code.
Remember to declare your counter!
Public Sub LoopExercise4A()
stockRet1 = Cells(4, 6).Value
stockRet2 = Cells(5, 6).Value
stockRet3 = Cells(6, 6).Value
End Sub
44. EXERCISE 4B. WRITE A FOR LOOP
Now, instead of using cell references use range
references to assign the array values:
Public Sub LoopExercise4A()
stockRet1 = Cells(4, 6).Value
stockRet2 = Cells(5, 6).Value
stockRet3 = Cells(6, 6).Value
End Sub
Public Sub LoopExercise4B()
stockRet1 = Range(“Returns”).Cells(1, 1)
stockRet2 = Range(“Returns”).Cells(2, 1)
stockRet3 = Range(“Returns”).Cells(3, 1)
End Sub
Exercise 4A
Exercise 4B
Check your array has correct values by either:
Outputting the array values to different cells (any cells)
Or by using a message box
Or by stepping through your code and checking the value
of each array element.
45. WRITE SUMS USING LOOPS & ARRAYS
sum = stockPrice(1) + stockPrice(2) + stockPrice(3)
46. WRITE SUMS USING LOOPS & ARRAYS
sum = stockPrice(1) + stockPrice(2) + stockPrice(3)
i=1
i = 1 sum = stockPrice(1)
47. WRITE SUMS USING LOOPS & ARRAYS
sum = stockPrice(1) + stockPrice(2) + stockPrice(3)
i=1
i=2
i = 1 sum = stockPrice(1)
i = 2 sum = sum + stockPrice(2)
48. WRITE SUMS USING LOOPS & ARRAYS
sum = stockPrice(1) + stockPrice(2) + stockPrice(3)
i=1
i=2
i=3
i = 1 sum = stockPrice(1)
i = 2 sum = sum + stockPrice(2)
i = 3 sum = sum + stockPrice(3)
49. WRITE SUMS USING LOOPS & ARRAYS
sum = stockPrice(1) + stockPrice(2) + stockPrice(3)
i=1
i=2
i=3
sum = 0
i = 1 sum = sum + stockPrice(1)
i = 2 sum = sum + stockPrice(2)
i = 3 sum = sum + stockPrice(3)
50. WRITE SUMS USING LOOPS & ARRAYS
sum = stockPrice(1) + stockPrice(2) + stockPrice(3)
Make sure the
sum starts at 0
51. EXERCISE 5. WRITE A FOR LOOP
Use Lecture 5 Student Example.xlsm
LoopExercise4B in Module1
Find the sum of the 3 stock returns you assigned to
an array in Exercise 4B using a For-Next loop.
Check your sum with a message box. If you get the
following result, you are correct:
52. LEARNING OUTCOMES
You are ready to move on when:
LO21: You can use loops and concatenation to assign values to
controls on a userform or assign cells, ranges or 1D arrays
values from userform controls.
LO22: You can describe what it means to generalise code. You
can also determine when loops should be generalised and how
to do so within your code.
LO23: You can define what a nested loop is. You can also
construct basic nested loops to output values to cells or ranges.
Lastly, given a nested loop you can determine the result.
LO24: You can describe the difference between a 1D and 2D
array. You can also declare an array with the correct number of
elements, in the correct location within your code and with the
correct data type. In addition, you understand when to declare
an array empty and how to use the ReDim statement.
LO25: You can assign values to a 1D array as well as assign the
values of a 1D array to cells, a range or userform controls.
