In visual basic, Keywords are the predefined set of reserved words that have special meaning for the compiler. So the keywords in visual basic cannot be used as identifiers such as variable name, class name, etc. in our applications.
In visual basic, Keywords are differentiated as two types, those are
Generally, the reserved keywords will not allow us to use them as names for programming elements such as variables, class, etc. In case, if we want to bypass this restriction, we need to define the variable name in brackets ([]).
Following table lists the available reserved keywords in Visual Basic programming language.
| AddHandler | AddressOf | Alias | And | AndAlso |
| As | Boolean | ByRef | Byte | ByVal |
| Call | Case | Catch | CBool | CByte |
| CChar | CDate | CDbl | CDec | Char |
| CInt | Class | CLng | CObj | Const |
| Continue | CSByte | CShort | CSng | CStr |
| CType | CUInt | CULng | CUShort | Date |
| Decimal | Declare | Default | Delegate | Dim |
| DirectCast | Do | Double | Each | Else |
| ElseIf | End | EndIf | Enum | Erase |
| Error | Event | Exit | False | Finally |
| For | For Each…Next | Friend | Function | Get |
| GetType | GetXMLNamespace | Global | GoSub | GoTo |
| Handles | If | Implements | Imports | In |
| Inherits | Integer | Interface | Is | IsNot |
| Let | Lib | Like | Long | Loop |
| Me | Mod | Module | MustInherit | MustOverride |
| MyBase | MyClass | Namespace | Narrowing | New |
| Next | Not | Nothing | NotInheritable | NotOverridable |
| Object | Of | On | Operator | Option |
| Optional | Or | OrElse | Out | Overloads |
| Overridable | Overrides | ParamArray | Partial | Private |
| Property | Protected | Public | RaiseEvent | ReadOnly |
| ReDim | REM | RemoveHandler | Resume | Return |
| SByte | Select | Set | Shadows | Shared |
| Short | Single | Static | Step | Stop |
| String | Structure | Sub | SyncLock | Then |
| Throw | To | True | Try | TryCast |
| TypeOf…Is | UInteger | ULong | UShort | Using |
| Variant | Wend | When | While | Widening |
| With | WithEvents | WriteOnly | Xor | #Else |
In visual basic, unreserved keywords are not a reserved keywords which means we can use them as names for programming elements such as variables, class, etc. However, it’s not recommended to use the keywords as programming elements because it will make your code hard to read and can lead to subtle errors that can be difficult to find.
Following table lists the available unserved keywords in visual basic programming language.
| Aggregate | Ansi | Assembly | Async | Auto |
| Await | Binary | Compare | Custom | Distinct |
| Equals | Explicit | Group By | Group Join | Into |
| IsFalse | IsTrue | Iterator | Join | Key |
| Mid | Off | Order By | Preserve | Skip |
| Skip While | Strict | Take | Take While | Text |
| Unicode | Until | Where | Yield | #ExternalSource |
In case, if you want to use a Keywords as variable names (identifiers), then we need to enclose the variable name in brackets ([]). For example, [Class] is a valid identifier but Class is not because it’s a keyword and having a special meaning for the compiler.
Following is the example of using the reserve keywords as a variable name by enclosing the variable name with brackets ([]) in visual basic.
Module Module1
Public Class [Class]
Public age As Integer
End Class
Sub Main()
Dim p1 As [Class] = New [Class]()
p1.age = 10
Console.WriteLine("Age: " & p1.age)
Console.WriteLine("Press Enter Key to Exit..")
Console.ReadLine()
End Sub
End Module
If you observe the above example, we used a Class keyword as a variable name ([Class]) by enclosing it with brackets ([]).
When we execute the above visual basic program, we will get the result like as shown below.
Age: 10
Press Enter Key to Exit..
This is how we can use the keywords as a variable name in visual basic based on our requirements.