Which event is triggered when a user presses a key while a TextBox control has the focus in a Visual Basic application?
a) KeyPress
b) KeyDown
c) KeyUp
d) KeyAction
Explanation: The "KeyDown" event is triggered when a user presses a key while a TextBox control has the focus in a Visual Basic application, allowing you to respond to keyboard input.
What is the purpose of the "Try...Catch" block in Visual Basic?
a) It is used to define a loop that executes a block of code repeatedly.
b) It specifies the entry point of the application.
c) It is used to handle exceptions and errors that might occur during the execution of code.
d) It defines the attributes and behaviors of a class.
Explanation: Exception handling for graceful error management.
In Visual Basic, which control is used to display a pop-up message with multiple lines of text?
a) AlertBox
b) PopupBox
c) MessageBox
d) PromptDialog
Explanation: In Visual Basic, the "MessageBox" control is used to display a pop-up message with multiple lines of text, providing informative messages or asking for user input.
What is the purpose of the "Not" operator in Visual Basic?
a) It performs bitwise negation on numeric values.
b) It reverses the logical state of a Boolean expression.
c) It checks whether a variable is null or empty.
d) It is used to concatenate strings.
Explanation: The "Not" operator in Visual Basic is used to reverse the logical state of a Boolean expression, making "True" to "False" and vice versa.
Which method is used to close a Visual Basic form programmatically?
a) Close()
b) Dispose ()
c) Hide()
d) EndForm ()
Explanation: The "Close()" method is used to programmatically close a Visual Basic form, triggering the FormClosing and FormClosed events.
How do you add a new item to a ComboBox control in Visual Basic?
a) comboBox.Items.Add("New Item")
b) comboBox.NewItem("New Item")
c) comboBox.Add("New Item")
d) comboBox.AddItem("New Item")
Explanation: To add a new item to a ComboBox control in Visual Basic, you use "comboBox.Items.Add("New Item")", where "comboBox" is the control's name and "New Item" is the text to be added.
