Question

Beginner question. How come I can do this:

Public Class Form1
    Private StudentsInMyRoom As New ArrayList

    Public Class student
        Public name As String
        Public courses As ArrayList
    End Class

    Private Sub btnCreateStudent_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnCreateStudent.Click

        Dim objStudent As New student
        objStudent.name = "Ivan"
        objStudent.courses = New ArrayList
        StudentsInMyRoom.Add(objStudent)
    End Sub

End Class

But I CANNOT do this:

Public Class Form1
    Private StudentsInMyRoom As New ArrayList

    Public Class student
        Public name As String
        Public courses As ArrayList
    End Class


    Dim objStudent As New student
    objStudent.name = "Ivan"
    objStudent.courses = New ArrayList
    StudentsInMyRoom.Add(objStudent)

End Class

In the second example, all of the objStudent.etc get squiggly underlined and it says “declaration expected” when I hover over it. It’s the same code except now it is not tied to clicking a button. Can’t figure out what is the difference.

Answer 1

It’s because the implementation needs to be in a method, the way you have it means the code couldn’t possibly be executed, how would you reference this code from elsewhere?

It doesn’t have to be tied to a click however:

    Private Sub AnyNameYouLike
        Dim objStudent As New student
        objStudent.name = "Ivan"
        objStudent.courses = New ArrayList
        StudentsInMyRoom.Add(objStudent)
    End Sub

Will work.