Imports System.Data.OleDb Private Sub btnInsert_Click(sender As Object, e As EventArgs) Handles btnInsert.Click ' Step 1: Connection string Dim connString As String = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\BCA_Lab\CollegeDB.accdb" Dim conn As New OleDbConnection(connString)
Remember the golden rule: Whether you are dealing with a misplaced Handles clause, a missing database parameter, or a logical off-by-one error, the solutions are standard and repeatable.
Ensure you add the first two terms before the loop. Never put them inside. 2. Program: Swap Two Numbers (Using ByRef) Common Problem: The swap doesn't work; numbers remain unchanged after calling the function. vb net lab programs for bca students fix
Wrong:
' Correct Procedure Sub Swap(ByRef x As Integer, ByRef y As Integer) Dim temp As Integer temp = x x = y y = temp End Sub ' Button Click Event Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click Dim num1 As Integer = Val(TextBox1.Text) Dim num2 As Integer = Val(TextBox2.Text) Swap(num1, num2) ' Now this modifies the original variables TextBox1.Text = num1 TextBox2.Text = num2 End Sub Imports System
ByVal sends a copy ; ByRef sends the memory address . 3. Program: Palindrome Checker (String & Integer) Common Problem: "Madam" returns false, but "radar" returns true. Case sensitivity fails.
Dim a As Integer = 0, b As Integer = 1, c As Integer, i As Integer Dim n As Integer = Val(TextBox1.Text) ' Number of terms ListBox1.Items.Clear() ListBox1.Items.Add(a) ' First term ListBox1.Items.Add(b) ' Second term For i = 3 To n c = a + b ListBox1.Items.Add(c) a = b b = c Next Dim a As Integer = 0
Normalize the string by converting to lowercase and removing spaces/punctuation.