End Class
: Always use input validation ( IsNumeric ) and explicit conversion methods like Convert.ToDouble() or Double.TryParse() to safely parse data before performing math operations.
The Visual Studio compiler marks syntax errors with a blue wavy line under the offending statement. When you hover over the marked code, an error message appears explaining the issue.
Private Sub LoadData() Dim connectionString As String = "Data Source=(localdb)\MSSQLLocalDB;Initial Catalog=YourDatabase;Integrated Security=True" vb net lab programs for bca students fix
2 TextBoxes, 4 Buttons (Add, Sub, Mul, Div), 1 Label (Result).
Crashing with an InvalidCastException or FormatException when a student leaves a TextBox blank or types text instead of numbers.
Module Module1 Sub Main() Dim input As String, reversed As String = "" Dim i As Integer Console.Write("Enter a string: ") input = Console.ReadLine() End Class : Always use input validation (
Private Sub btnInsert_Click(sender As Object, e As EventArgs) Handles btnInsert.Click Try con.Open() Dim cmd As New SqlCommand("INSERT INTO Student (ID, Name, Course) VALUES (@id, @name, @course)", con)
' Convert string array to integer array For i As Integer = 0 To input.Length - 1 numbers(i) = Integer.Parse(input(i).Trim()) Next
: Always write Option Explicit On and Option Strict On at the very top of your code windows. While this forces you to write cleaner code by preventing implicit type conversions, it prevents subtle logic bugs that can penalize your practical exam scores. Private Sub LoadData() Dim connectionString As String =
Ultimate VB.NET Lab Programs Guide for BCA Students: Code & Fixes
' Sort the array Array.Sort(numbers)
This program demonstrates standard event handling using Windows Forms. It takes two numbers from the user and performs basic arithmetic operations. Complete Code