Exam 10: Structures and Sequential Access Files

Write the code to declare a variable named outFile that can be used to write data to a sequential access file. Then write the statement to open a sequential access file named samples.txt for output. New data should be written to the file after any existing data in the file.

Describe two advantages to programmers of using structures and structure variables.

Which of the following statements can be used to fill a string variable with asterisks resulting in "*****$675.89"?

Most programmers use the Structure statement, rather than the Class statement, to create data types that contain procedures.

Programmers refer to a sequence of characters as a ____.

Write the code to declare a variable named inFile that can be used to read data from a sequential access file. Then write the statement to open a sequential access file named samples.txt for input.

The syntax used to declare a StreamWriter variable is ____.

To access a member of a structure variable in an array, you use the syntax ____.

A file to which information is written is referred to as a(n) ____ file.

Which of the following can be used to determine whether the accounts.txt file exists?

Data types created using the Structure statement are referred to as user-defined data types or structures.

Which of the following statements will write the text "Programming" to a sequential access file?

Write a Do clause that reads each line of text in a sequential access file and assigns the line to the strTextLine variable. Process the loop until the end of the file has been reached. The file is associated with a StreamReader variable named inFile .

A(n) ____ is defined as a sequence (stream) of characters followed by the newline character.

Variables declared using a structure are often referred to as ____.

Problems - Correcting Logic and Code Errors The following sample of code contains errors. Rewrite the incorrect statements to correct all errors. Private Sub btnDisplay_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnDisplay.Click ' display the contents of the students.txt file ' declare variables Dim inFile As IO.StreamWriter Dim strStudent As String ' clear previous students from the Students box lblStudents.Text = String.Empty ' determine whether the file exists If IO.Exists("students.txt") = True Then ' open the file for input inFile = IO.File.ReadText("students.txt") ' process loop instructions until end of file Do Until inFile.Peek -1 ' read a student line strStudent = inFile.ReadLine ' display the student lblStudents.Text = lblStudents.Text & strStudent & ControlChars.NewLine Loop ' close the file Me.Close() Else MessageBox.Show("File not found","Students", MessageBoxButtons.OK, MessageBoxIcon.Information) End If End Sub

You can use the ____ to open a sequential access file for append.

Which of the following opens the employee.txt file for output, creates a StreamWriter object, and assigns it to the outFile variable?

The Peek method, looks ahead into the file to determine whether the file contains another character to read.

The members of a structure can be variables, constants, or ____.