Visual Basic 2012 Programmer's Reference

VARIABLE DECLARATIONS

The complete syntax for a variable declaration is as follows:

[attribute_list] [accessibility] [Shared] [Shadows] [ReadOnly]
Dim [WithEvents] name [(bounds_list)] [As [New] type]
[= initialization_expression]

All declarations have only one thing in common: They contain a variable’s name. Other than the name, different declarations may have nothing in common. Variable declarations with different forms can use or omit any other piece of the general declaration syntax. For example, the following two declarations don’t share a single keyword:

Dim i = 1           ' Declare private Integer named i. (Option Explicit Off)
Public j As Integer ' Declare public Integer named j.

The many variations supported by a variable declaration make the general syntax rather intimidating. In most cases, however, declarations are straightforward. The previous two declarations are fairly easy to understand.

The following sections describe the pieces of the general declaration in detail.

Attribute_List

The optional attribute list is a comma-separated list of attributes that apply to the variable. An attribute further refines the definition of a variable to give more information to the compiler and the runtime system.

Attributes are rather specialized and address issues that arise when you perform very specific programming tasks. For example, when you write code to serialize and de-serialize data, you can use serialization attributes to gain more control over the process.

The following code defines ...