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VB.NET Language in a Nutshell, Second Edition by Steven Roman PhD, Paul Lomax, Ron Petrusha

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Name

CObj Function

Named Arguments

No

Syntax

CObj(expression)
expression (required; any)

Return Value

expression cast as an Object data type

Description

Converts any expression that can be interpreted as an object to Object

Rules at a Glance

expression can be any data type, including a strongly typed object, as the following code fragment illustrates:

Dim oSomeClass As New CSomeClass
Dim oObj As Object
oObj = CObj(oSomeClass)

Example

The following code:

Dim obj As Object
obj = CObj("test")

casts the string "test" to type Object and places it in the Object variable obj.

Programming Tips and Gotchas

  • The operation of the CObj function is possible because all VB.NET data types are either structures or objects.

  • Once a data type is converted to type Object, you can display its value by calling its ToString method, as in the following code fragment:

    Dim bFlag As Boolean = True
    
    oObj = CObj(bFlag)
    MsgBox(oObj.ToString)
  • Instead of using the CObj function to convert a strongly typed object to a generic Object data type, you can also use simple assignment, as the following code fragment illustrates:

    Dim oSomeClass As New CSomeClass
    Dim oObj As Object
    oObj = oSomeClass
  • Like most of the conversion functions, CObj is not actually a function in the Microsoft.VisualBasic namespace. Instead, it is similar to a Visual C++ macro; the compiler translates the function call into inline code.

VB.NET/VB 6 Differences

The CObj function is new to VB.NET. The closest equivalent in VB 6 is CVar, which converts a data type ...

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