PT1420 File Access and Visual Basic .docx
- 1. PT1420: File Access and Visual Basic Page 1 This lab examines how to work with a file by writing Visual Basic code. Read the following programming problem prior to completing the lab. Write and design a simple program that will take 3 pieces of data and write it to a file. Create variables and set them equal to the appropriate values: Declare string firstName = “xxx” Declare string lastName = “xxx” Declare integer age = your age Write this information to a file called myRecords.txt. Next, read this information from the file and print it to the screen. Step 1: Create a new Visual Basic workspace and add the following code: Module Module1 Sub Main()
- 2. Dim firstName As String = "XXXX" Dim lastName As String = "XXX" Dim age As Integer = #### Dim writer As System.IO.StreamWriter = System.IO.File.CreateText("myRecords.txt") writer.WriteLine(firstName & " " & lastName & " " & age) writer.Close() Dim reader As System.IO.StreamReader = System.IO.File.OpenText("myRecords.txt") Dim myInfo As String = reader.ReadLine() Console.WriteLine(myInfo) PT1420: File Access and Visual Basic Page 2 reader.Close() 'this causes a pause so you can see your program Console.Write("Press enter to continue...") Console.ReadLine()
- 3. End Sub End Module Your module looks like this: PT1420: File Access and Visual Basic Page 3 Step 2: Change the values of the variables to your records. Your module looks like this: Step 3: Run your program so that it works properly. Your output might look as follows: PT1420: File Access and Visual Basic Page 4
- 4. Step 4: Locate the .txt file in the bindebug folder, and view your .txt file. Your output might look as follows: PT1420: File Access and Visual Basic Page 5 Step 5: Submit the Visual Basic code as a compressed (zipped) folder using the following steps: a. Open Windows Explorer --> Start --> All Programs --> Accessories --> Windows Explorer. Your Windows Explorer might look as follows: PT1420: File Access and Visual Basic Page 6
- 5. b. In Windows Explorer, navigate to the folder that contains your project files. Your Windows Explorer might look as follows: (If you don't recall you can check in Visual Studio by opening your project, right click module1.vb file and view the properties. Look at the full path ex. C:UsersinstructorDocumentsVisual Studio 2010ProjectsmyFirstProgrammyFirstProgramModule1.vb; in this case navigate to C:UsersinstructorDocumentsVisual Studio 2010Projects). Your module properties might look as follows: PT1420: File Access and Visual Basic Page 7 c. Right click on your project folder and choose send to -->
- 6. compressed folder. This creates a zip file of all your code. Your Windows Explorer might look as follows: d. Attach the compressed folder you created to your submission. Your Windows Explorer might look as follows: PT1420: Functions in Pseudocode and Visual Basic Writing Your Own Function that Returns an Integer Step 1:A function contains three parts: a header, a body, and a return statement. The first is a function header that specifies the data type of the value that is to be returned, the name of the function, and any parameter variables used by the function to accept arguments. The body is composed of one or more statements that are executed when the function is called. In the following space, complete the following: (Reference: Chapter 6, Writing Your Own Functions, page 225 of your textbook, Starting Out with Programming Logic & Design). 1. Write a function with the header named addTen. 1. The function will accept an Integer variable named number. 1. The function body will ask the user to enter a number and the add 10 to the number. The answer will be stored in the variable number. 1. The return statement will return the value of number. Function a.__________ a.____________ (b.______________) Display “Enter a number:” Input c._________________
- 7. Set c._____________ = number + 10 Return d.___________________ Step 2:In the following space, write a function call to your function from Step 1. Set number = ____________________ (__________________) Step 3: Launch and create a new workspace in Visual Basic. Place the following code inside and run the program. Notice there is already a call to addTen(number) and that the function call operates the same ways a module call does, except that a function call accepts a returned value. Therefore, the function call looks as number = addTen(number). Module Module1 Sub Main() Dim number As Integer = 0 number = addTen(number) Console.WriteLine("The number with 10 added to it is : " & number) Console.WriteLine("Press any key to continue...") Console.ReadLine() End Sub End Module Your module looks like this: Step 4: After End Sub in Main(), add a function by typing the following: Function addTen(ByVal number As Integer) When you hit enter, the End Function will automatically be added. All code in the function will be between Function and End Function. Step 5: Write a line of code that will allow the user to enter a number and then add the formula number = number + 10 based on the pseudocode in step 1 of this lab. Step 6: Before End Function, add a return statement that looks like: Return number
- 8. Now, your module looks like this: Step 7: Run your program so that if works properly. Your output might look as follow: Using Mathematical Library Function: sqrt Step 8:The sqrt function accepts an argument and returns the square root of the argument. In the following space, complete the following: (Reference: The sqrt Function, page 240 of your textbook, Starting Out with Programming Logic & Design). 1. Declare a variable named myNumber and a variable named squareRoot of the data type Real. 1. Ask the user to enter a number of which they want to find the square root. Store the input in myNumber. 1. Call the sqrt function to determine the square root of myNumber. 1. Display the square root to the screen. Declare Real a.___________________ Declare Real a.______________________ Display “Enter a number:” Input b._________________________ Set c.______________ = _______________________ Display “The square root is”, d.____________________ Step 9: Using the same Visual Basic workspace, under the output from your previous lab, declare and initialize myNumber and squareRoot as doubles set equal to 0. Step 10: Write a line of code that will allow the user to enter in a value for myNumber. Step 11: Next, add the following line of code which calls the System.Math.Sqrt() function: squareRoot = System.Math.Sqrt(myNumber) Also note the many other Math functions available for use. Step 12: Add a line of code that will display the value of
- 9. squareRoot. Step 13: Run your program so that if works properly. Your output might look as follow: Step 14: Submit the Visual Basic code as a compressed (zipped) folder using the following steps: 1. Open Windows Explorer --> Start --> All Programs --> Accessories --> Windows Explorer. Your Windows Explorer might look as follows: 1. In Windows Explorer, navigate to the folder that contains your project files. Your Windows Explorer might look as follows: (If you don't recall you can check in Visual Studio by opening your project, right click module1.vb file and view the properties. Look at the full path ex. C:UsersinstructorDocumentsVisual Studio 2010ProjectsmyFirstProgrammyFirstProgramModule1.vb; in this case navigate to C:UsersinstructorDocumentsVisual Studio 2010Projects). Your module properties might look as follows: 1. Right click on your project folder and choose send to --> compressed folder. This creates a zip file of all your code. Your Windows Explorer might look as follows:
- 10. 1. Attach the compressed folder you created to your submission. Your Windows Explorer might look as follows: Page 1