ISM 3253 Exam I Spring 2009

Transcription

1 ISM 3253 Exam I Spring 2009 Directions: You have exactly 75 minutes to complete this test. Time available is part of the exam conditions and all work must cease when "Stop work" is announced. Failing to stop at the first announcement will result in a 10% penalty. Failing to stop at the second announcement will be a 100% penalty. Be sure to read each question carefully. Determine what is being asked. Some questions ask for more than one response from you. You do not need to provide any information that is not specifically asked for in the question. You may separate the exam pages if you would like but there will be a penalty for not reassembling them in the proper order. Some questions may have multiple correct answers. You only need to provide one correct answer unless specifically told otherwise. Partial credit will be given. Coding Rules: 1. Do not comment your code 2. Do use appropriate variable and control naming. 3. All variables must be declared unless the question states otherwise. 1. (10 points) Refer to the form to the right. What will be the contents of the label lblone.text and lbltwo.text when the code for the btnanswer Click event finishes running? Control names are shown in the labels next to the controls. Name (Print) Private Sub btnanswer_click(byval sender As System.Object, _ ByVal e As System.EventArgs) Handles btnanswer.click Dim intone As Integer Dim inttwo As Integer = 2 intone = Val(txtOne.Text) intone = intone + inttwo lblone.text = intone.tostring inttwo = inttwo + intone lbltwo.text = inttwo.tostring End Sub lblone.text lbltwo.text

2 2. (10 points) List five control types with a property of that control that can be directly changed by user action when the form is running Control Property 3. (6 points) Pick one of the properties you specified above that can accept a string value. Write a line of code to set this property to the value of the variable called strvariable. Assume that the variable has already been appropriately declared and set with a value from previous code. 4. (6 points) Name a control type and property that can be directly affected by user interaction where the property contains a Boolean (True/False) value. 5. (6 points) Name two controls needing event code in Homework #3 and the event for each that you will use. The two controls must be of different types Control Event 2

3 6. (8 points) Consider the VB code and chart below. If btnquestion6 is clicked two times with the values for txtinput shown in the chart indicate the values that will be set into the three labels each time the button is pushed. Assume that the program continues to run (it is not shut down) for each execution of the event. Public Class Form1 Dim intfirst As Integer Private Sub btnquestion6_click(byval sender As System.Object, _ ByVal e As System.EventArgs) Handles btnquestion6.click Dim intsecond as Integer intfirst = intfirst + intsecond lblfirst.text = intfirst.tostring intsecond = Val(txtInput.Text) lblsecond.text = intsecond.tostring intfirst = intfirst + intsecond lblthird.text = intfirst.tostring End Sub End Class Click # txtinput lblfirst lblsecond lblthird (5 points) Write the following math expression using VB syntax using x as a variable name in the VB: 8. (10 points) If x = 5 and y = 2 what is the value of the following VB expressions? a. x + (5 * y) / x y b. (4 ^ y / 2 + x) * y / 4 3

4 9. (10 points) Refer to the form below with two textboxes, txtprice and txtqty and the button btntotal. Write code for the TextChanged event below that will enable the button if both text boxes contain numeric values > 0 and are not empty and which will disable the button if either text box is not numeric or is empty. Note that the event code template below will execute if the.text property of either text box changes. The enabled status of the button is set with the btntotal.enabled property which may be set to either True or False. As shown the button s initial.enabled property value is False. Private Sub txtprice_textchanged(byval sender As System.Object, _ ByVal e As System.EventArgs) _ Handles txtprice.textchanged, txtqty.textchanged 4

5 10. (10 points) Assume that the variable stralumni will always contain a former student s Social Security Number as a 9- digit string of numbers, the Last Name in a 20-character string filled with spaces if necessary, and the first name as a 15- character string also padded with spaces if necessary. Three sample values for stralumni might look like this Jones Willimina Frederickson-Smith Joe Alberts Billy-Bob Assume that the variable stralumni has already been declared and loaded with a value. Write the code to extract just the first and last names from this string and store them without any spaces into the variables called strfirstname and strlastname. Your code must work for any value of stralumni following these formatting rules, not just one of the samples shown above. You do not need to write any Sub or End Sub statements. 11. (10 points) While I almost never give True/False exams I will make an exception for this case. Evaluate the expressions below and determine whether they are True or False: a. (TRUE AND FALSE) OR (TRUE OR FALSE) b. NOT FALSE OR (FALSE OR TRUE) OR FALSE c. (FALSE OR NOT TRUE OR FALSE) 5

6 12. (10 points) Consider the form to the right which contains a list of student class standing titles in a list box called lststatus. Students get different start times for course registration depending on their standing as shown below. Senior Junior Sophomore Freshman 8:00 AM 11:00 AM 2:00 PM 5:00 PM Write code for the btntime Click event that will load the start time as a string for the selected status into the label lblstarttime. lststatus.text will give you the text of the item the user has selected while lststatus.selectedindex will give the position in the list (starting with zero) of the item the user has selected. Do not attempt to treat the start time as a date-time value as we have not covered this yet. Just treat it as a string. Private Sub btntime_click(byval sender As System.Object, _ ByVal e As System.EventArgs) Handles btntime.click End Sub 6

7 ISM 3253 Exam II Fall 2009 Dr. West Directions: You have exactly 75 minutes to complete this test. Time available is part of the exam conditions and all work must cease when "Stop work" is announced. Failing to stop at the first announcement will result in a 10% penalty. Failing to stop at the second announcement will be a 100% penalty. Be sure to read each question carefully. Determine what is being asked. Some questions ask for more than one response from you. You do not need to provide any information that is not specifically asked for in the question. You may separate the exam pages if you would like but there will be a penalty for not reassembling them in the proper order. Some questions may have multiple correct answers. You only need to provide one correct answer unless specifically told otherwise. Partial credit will be given. Coding Rules: 1. Do not comment your code 2. Do use appropriate variable and control naming when appropriate 3. All variables must be declared unless the question states otherwise. Name (Print) 1. (11 points) Consider the four sections of code below. For each, indicate what will be displayed in Label1.Text when the code has finished. Just write your answer inside the box containing the code. Dim intcount as Integer Dim x as Integer For x = 0 to 4 intcount += 3 Next x Label1.Text = intcount.tostring Dim intcount as Integer intcount = 0 Do While intcount < 5 intcount += 1 Loop Label1.Text = intcount.tostring Label1.Text = Dim intcount as Integer Dim x as Integer For x = 0 to 3 intcount += x Next x Label1.Text = x Label1.Text = Dim intcount as Integer intcount = 0 Do Until intcount > 5 intcount += intcount Loop Label1.Text = intcount.tostring Label1.Text = Label1.Text =

8 2. (11 points) Assume that you are modifying an existing application and that the application creates a single-dimension array called sglprices( ) of type Single that is sized and populated elsewhere in the application code. Write code that will total all of the values in the array and store the total into a variable called sgltotal. 3. (11 points) Assume that you are writing code on FormA to show FormB. Write three different examples of code on FormA that will show FormB while making FormA unavailable for user interaction. 2

9 4. (11 points) Assume that your application code has the two-dimensioned string array called strtrans scoped at the module level. This array is used to hold the values for our checkbook program instead of using independent arrays. In addition, the variables sglbalance and intcount are scoped at the module level and sglbalance was filled by the btnsave code just as should have been done in HW #3 & #4. Remember that the check number text box contains Dep if the transaction is a deposit. Each btnrecord_click event executes the following code: ReDim Preserve strtrans(4, intcount) strtrans(0, intcount) = txtchecknum.text strtrans(1, intcount) = dtptransdate.text strtrans(2, intcount) = txtpayee.text strtrans(3, intcount) = txtpurpose.text strtrans(4, intcount) = txtamount.text intcount = intcount + 1 Write the code to calculate the total balance in the account if the starting balance is stored in a variable called sglbalance. This code will run AFTER the code shown above. 3

10 5. (11 points) Consider the structure of the Try End Try block shown below: Try Catch ex As OverflowException Catch ex As IndexOutOfRangeException Catch ex As Exception Finally End Try a. What happens if an error occurs between the Try statement and the first Catch statement? b. Why are there multiple Catch statements inside this block? c. Why should any Try End Try include a Catch ex As Exception statement and why should this statement be the last Catch statement in the block? d. If the Finally statement is present, when will the code between Finally and End Try execute? 4

11 6. (11 points) Write a function that will receive as two passed parameters an integer value for starting mileage, a second integer value for ending mileage, and a single precision value for gallons used. The function must return the miles per gallon achieved for these values as a single precision value 7. (11 points) Write a subroutine that will receive two integer values as passed parameters and display the lowest of the two values in the text box txtresult. 5

12 8. (11 points) Any form in a multiform application can reference any other form in two ways, by referring to the form by name in code or by creating an object variable instance of the other form and referring to the object variable instance. What are the differences between using these two techniques for referencing one form from another form? 9. (11 points) Homework #3 & #4 required you to write a subroutine that would receive an entire text box control as a passed parameter as well as a validation string (e.g., ) and validate the text box s contents to ensure that it contained characters in the validation string. What is the advantage of writing this code in a subroutine instead of putting the validation code in the TextChanged event of each text box on the form? 6

13 ISM 3253 Final Exam Fall 2009 Section 01 Directions: You have exactly 105 minutes (1 hour 45 minutes) to complete this exam. Time available is part of the exam conditions and all work must cease when "Stop work" is announced. Failing to stop at the first announcement will result in a 10% penalty. Failing to stop at the second announcement will be a 100% penalty. Be sure to read each question carefully. Determine what is being asked. Some questions ask for more than one response from you. You do not need to provide any information that is not specifically asked for in the question. Some questions may have multiple correct answers. You only need to provide one correct answer unless specifically told otherwise. Partial credit will be given. Coding Rules: 1. Do not comment your code 2. Do use appropriate variable and control naming when appropriate 3. All variables you create must be declared unless the question states otherwise. Name (Print)

14 1. Assume that the variable strinfo will always contain the Product ID as a 4 character string containing a number, a colon, the Product Name (which may include spaces), a colon, the Product Price with just numbers and a decimal point, a colon, and the quantity currently in stock. Two sample values for strinfo might look like this 0012:Joe s Pickled Gopher Gizzards:34.56: :Wanda s Candied Dragonfly Hearts:19.95:4567 Write the code to extract just the product name from this string and store it into a variable called strname. You do not need to write any Sub header for the code. 2. Write a function that will receive as two passed parameters a single precision value for product price and an integer value for quantity. The function must return the total amount owed for this item including a sales tax of 6%. You must write the entire function structure including the Function and End Function lines. 2

15 3. Assume that your application code has the two-dimensioned string array called strtrans scoped at the module level. This array is used to hold the values for our checkbook program instead of using independent arrays. In addition, the variables sglstartbalance and intcount are scoped at the module level. sglstartbalance is set one time elsewhere in the code and is not changed by any code. Remember that the check number text box contains Dep if the transaction is a deposit. Each btnrecord_click event executes the following code: ReDim Preserve strtrans(4, intcount) strtrans(0, intcount) = txtchecknum.text strtrans(1, intcount) = dtptransdate.text strtrans(2, intcount) = txtpayee.text strtrans(3, intcount) = txtpurpose.text strtrans(4, intcount) = txtamount.text intcount = intcount + 1 Write the code to calculate the total balance in the account if the starting balance is stored in a local variable called sglbalance. This code will run AFTER the code shown above. You must recalculate the new balance from values stored in the array and sglstartbalance. 3

16 4. Assume that an employee s record has been loaded from a data file and that the variable dtbirthdate contains a date value for the employee s birth date. Write the code to set the employee s current age in years into an integer variable called intage. 5. What is the difference in behavior between the following two lines of code if the file f:\sample.txt already exists? A. Dim fstest As New FileStream( f:\sample.txt, FileMode.Append, FileAcces.Write) B. Dim fstest As New FileStream( f:\sample.txt, FileMode.Create, FileAcces.Write) 6. Answer each of the questions below: A. What value to programmers do classes, user defined controls (user controls), and dynamic link library (DLL) projects have in common? B. When working with sequential data files we had to add the statement Imports System.IO to a form. On the last day of class we saw the statement Imports System.Data.SQLClient. What capability that was demonstrated does this statement provide? 4

17 Questions 7 & 8 Refer to the Form and Data File on page 9 of the exam only. Do not consider the class definition on page 10 when answering these two questions. 7. Refer to the Peer Evaluation form and data file for the peer evaluation application. Write all of the code for the btnsave Click event to record a rating in the file. You do not need to perform any validation in this code. Remember that names must be concatenated to the form First-space-Last for writing and that the rated student s name is the first one in the record followed by the rating student s name second. Private Sub btnsave_click(byval sender As System.Object, _ ByVal e As System.EventArgs) Handles btnsave.click 5

18 8. Write all of the code for the btnaverages button click event on the Peer Scores form to calculate the effort, effectiveness, and overall average scores for the student named in the text boxes and display the results in the appropriate labels. Remember that the rated student s name is the first one in the list. Private Sub btnaverages_click(byval sender As System.Object, _ ByVal e As System.EventArgs) Handles btnaverages.click 6

19 Questions 9 & 10 Refer to the Form and Data File on page 9 and the class definition on page Refer to the sample form and data file and class definition for the peer evaluation program. Write an Effort property for the class that will receive and validate a score for effort according to the rules listed below. If the score is valid it must be passed through to the private variable m_sgleffort. The property must also allow reading m_sgleffort. A. The score can never be negative (zero is allowed) B. The score cannot be greater than ten C. The score must be numeric D. The score must exist 7

20 10. Refer to the sample form and data file and class definition for the peer evaluation application and note the empty WriteRecord method (Sub) in the class. Assume that this method contains the correct code for writing a record to the data file (very similar to your answer to Question #7) except that the code uses the member variables shown in the class (m_strratedlast, etc.) as the values to be written. Write the declaration for the class and the code for the Click Event of the btnsave button on the form that will save an evaluation into the data file using the capabilities of the class. Your code must test the status of the class error property before executing the actual save. You are not writing the actual class code to execute the write operation. You are writing code on the form file. Public Class PeerEvaluations Private Sub btnsave_click(byval sender As System.Object, _ ByVal e As System.EventArgs) Handles btnsave.click 8

21 You may remove this page from the exam if you wish. Some of the exam questions refer to the forms and data file illustrated below. The data mimics that used in peer evaluations in my classes where students work in project teams. Each student rates each of their teammates on a 0-10 scale on both Effort and Effectiveness. The data file shows a sample of transactions. Assume that all data in the file is for one class only. Textbox and relevant label names are shown as the.text properties for the controls in the screen shots. Note that even though names are entered separately as First and Last they are recorded as First-space-Last. Also note that the rated student s name is the first name in the data record. c:\rating.txt Joe Smith Wanda McGillicutty 8 5 Sally Jones Marty Alberts Joe Smith Mary Cunningham 6 5 : : Wanda McGillicutty Joe Smith 10 2 Mary Cunningham Al Hirt 9 8 Remember the rated student is the first of the two names while the student giving the rating is the second. 9

22 Imports System.IO Public Class FinalExamClass Private m_strratedfirst As String Private m_strratedlast As String Private m_strratingfirst As String Private m_strratinglast As String Private m_sgleffort As Single Private m_sgleffect As Single Private m_blniserror As Boolean Public ReadOnly Property IsError() As Boolean Get Return m_blniserror End Get End Property Public Property RatedFirst() As String Get Return m_strratedfirst End Get Set(ByVal value As String) If Len(Trim(value)) > 0 Then m_strratedfirst = value Else m_blniserror = True m_strratedfirst = "" End If End Set End Property Public Property RatedLast() As String Public Property RatingFirst() As String Public Property RatingLast() As String Public Property Effort() As String Public Property Effect() As String Public Sub WriteRecord() End Sub Code details for the properties to the left have been omitted. Code details for the method to the left have been omitted End Class 10