: Creating a Digital Watch , blinking images, or continuous scrolling text animations. Advanced GUI & Data Handling :

to avoid comparing the last element with a non-existent index. Program: Database Connection (ADO.NET)

Imports System Module PrimeProgram Sub Main() Dim num As Integer Dim isPrime As Boolean = True Console.Write("Enter an integer to check: ") If Integer.TryParse(Console.ReadLine(), num) Then If num <= 1 Then isPrime = False Else ' Optimize loop by checking up to the square root For i As Integer = 2 To Convert.ToInt32(Math.Sqrt(num)) If num Mod i = 0 Then isPrime = False Exit For End If Next End If If isPrime Then Console.WriteLine($"num is a Prime Number.") Else Console.WriteLine($"num is not a Prime Number.") End If Else Console.WriteLine("Invalid input. Please enter a valid integer.") End If Console.ReadLine() End Sub End Module Use code with caution. 2. Object-Oriented Programming (OOP) Applications

| Issue | Symptoms | Solution | |-------|----------|----------| | NullReferenceException with objects | “Object reference not set to an instance of an object” | Ensure you use Dim obj As New ClassName() before accessing members | | Shared vs instance confusion | Method calls don’t work as expected | Remember: shared methods can be called without an instance ( ClassName.Method() ), instance methods require an object ( obj.Method() ) | | Access level violations | Compiler errors about inaccessible members | Review Public , Private , Friend , and Protected keywords | | Constructor not firing | Properties not initialized | Verify the Sub New() is Public and not overridden |