The difference between Shared, Public, etc.

cqpzj7788

Shared
Public
Protected
Friend
Private
...

The scope of application, please give a simple example to illustrate

cqpzj7788

Can use the scope of the current class, project, etc.

杀人放血

public, private, protect are the scope of variable
Shared variables are similar to application global variables.

cloud31

Shared is similar to static

irwin8888

Shared declares static global variables, multi-threaded can be used as safe variables
Public global variable, this variable can be used wherever it is declared
Protected seems to be used for declaring attributes, right? Preceded by public is globally visible, plus private module is visible inside
Friend doesn't know this thing very much, it is used in front of the attribute. . . Not used
Private local variables can only be seen in this module, and their functions are basically the same as dim. . . But no one declared that the method should use dim. . . This is the difference.

黑与白的礼赞

Class Employee
    Public name As String
    Private salary As Double
End Class

Module MDLTest
    Sub Main()
        Dim c As New Employee
        c.name = "John"
        'Error:
        'c.salary = 100403.33
    End Sub
End Module
-------------------------------------------------- -------------
Class Client
    Public prefix As String
    Public name As String
    Public Shared printPrefix As Boolean = True
    Sub PrintName()
        If printPrefix Then Console.Write(prefix)
        Console.WriteLine(name)
    End Sub
End Class

Module MDLTest
    Sub Main()
        Dim x As New Client
        x.prefix = "Mr."
        x.name = "John Smith"

        Client.printPrefix = False
        x.PrintName()
    End Sub
End Module

yuleisme

Public, protected, friend, and private define the access rights of members in the class.

Other members, subclasses, instances, and friends of the public class can all be accessed
Other members of the protected class, subclasses can access
Other members of the friend class, the friend class can visit
Other members in the private class can access

Shared declares that members are shared, which is equivalent to static (static) in c++, c#, and java, and cannot be accessed in the instance. It can only be accessed by type. And its value is shared. Can be modified. This point is completely different from const.