2
Visual Studio.NET, , , .
( 5) ( ). . .
.
.
, .
.
VB.NET 255 Unicode ( Unicode www.unicode.org), . , . , ; , firstBase firstbase . =
theYear = 2001
.NET Framework . , MSDN, , ( , i t) .
, VB.NET ( . 4.1), , . , Loop, [Loop] . (, loopit ). VB.NET ( ).
4.1.
AddressOf | Alias | And | Ansi | As |
Assembly | Auto | Binary | BitAnd | Byte |
BitNot | BitOr BitXor | Boolean | ByRef | ByVal |
Call | Case | Catch | CBool | CByte |
CChar | CDate | CDec | Class | CLng |
CDbl | Char | CInt | CObj | Compare |
Const | CShort | CSng | CStr | Ctype |
Date | Decimal | Declare | Default | Delegate |
Dim | Do | Double | Each | Else |
Elself | End | Enum | Erase | Error |
Event | Exit | Explicit | ExternalSource | False |
Finally | For | Friend | Function | Get |
GetType | GoTo | Handles | If | Implements |
Imports | In | Inherits | Integer | Interface |
Is | Lib | Like | Long | Loop |
Me | Mod | Module | Mustlnherit | MustOverride |
MyBase | MyClass | Namespace | Next | New |
Not | Nothing | Notlnheritable | NotOverridable | Object |
Off | On | Option | Optional | Or |
Overloads | Overridable | Overides | ParamArray | Preserve |
Private | Property | Protected | Public | RaiseEvent |
Readonly | ReDim | REM | RemoveHandler | Resume |
Return | Select Set | Shadows | Shared | Short |
Single | Static | Step | Stop | Strict |
String | Structure | Sub | SyncLock | Text |
Then | Throw | To | True | Try |
TypeOf | Unicode | Until | When | While |
With | With | Events | WriteOnly | Xor |
|
|
, .
, , , . , , 3 3 . 3 ? ? 3 2 , .
, , , , . 3. VB.NET ( ):
: , .
: Integer.
.NET: Long ( 4 ).
, 3 ( VB). VB.NET .
3 . , VB.NET, , . , 31 Integer 3, "3" String ( String ).
, VB.NET System.
, , . VB.NET.
Byte: 1- 0 255.
Short: 2- -32 768 32 767, Integer VB. Short S , 237S.
Integer: 4- -2 147 483 648 2 147 483 647, Long VB. Integer I , 2371.
, Integer, Integer. , 32- Integer .
|
|
Long: 8- -9 223 372 036 854 775 808 9 223 372 036 854 775 807. VB. Long L , 2371.
:
Single: 4- . Single F , 1.23F 3F.
Double: 8- . , Double. , Double Single; 32- Double .
Decimal: 12- , 28 . , Decimal 79 228 162 514 264 337 593 543 950 335, , 28. , , Decimal, 0.0000000000000000000000000001. Decimal D.
, . :
Console.WriteLine(12345678 * 4567)
:
This constant expression produces a value that is not representable in type System.Integer.
Long:
Console.WriteLine(123456781 * 4567)
MaxValue MinValue, , . :
Console.WriteLine(Integer.MaxValue)
4.2 VB.NET, .NET Framework VB6 ( ).
3.2.
VB. NET .NET Framework
Byte System. Byte
Boolean System. Boolean
Decimal System. Decimal
Double System. Double
Short System. Intl6
Integer System.Int32
Long System.Int64
Single System. Single
Boolean,Date Char. Bool ean True False. VB.NET 4 .
VB.NET - 1 True +1 ( .NET). - 2 -1. , True -1, 1. VB.NET VB, 1. , , , .NET, . True False, , .
Date / . #...# , #Jan 1. 2001#. ), , .
Date VB.NET Double. , , , Today+1.
Char Unicode. Unicode (65 536 ) . , (, ""), Chr Unicode. , Chr(&H2153) 1/3 Unicode, . ѻ, String Char, ( Option Strict ).
|
|
VB.NET Dim As, =:
Dim foo As String
foo = "bar"
VB.NET, . VB.NET . :
Dim salesTax As Decimal = 0.0825D
salesTax 0.0825 Decimal. VB.NET. startAngle , System. Math: Dim startAngle As Decimal - Math.PI
, , , , 0. , VB.NET, , . &, VB :
Sub Main()
Dim salesTax As Double = 0.0825
Dim state As String = "California"
Console.WriteLine("The sales tax in " & state & " is " & salesTax)
Console. ReadLine()
End Sub
:
The sales tax in California is 0.0825
VB, , . , : i, j k, Integer:
Dim i, j, k As Integer
, :
Dim i, j, k As Integer = 1
VB, As . :
Dim i%, myname$
i Integer myName String. VB.NET .
, . ( ), . .NET Framework . , .
DefType (, Deflnt) VB.NET .
, VB . , VB6 Integer.
VB.NET Option Strict. , ( Strict Type Checking Build Project Properties):
|
|
Option Strict On
( !) VB.NET , , , . , Single Integer , Integer Single. , (, Integer Long Decimal), VB.NET . VB.NET (widening conversions). 4.3 .
4.3. VB.NET
Byte | Byte, Short, Integer, Long, Decimal Single, Double |
Short | Short, Integer, Long, Decimal, Single, Double |
Integer | Integer, Long, DecimaL Single, Double |
Long | Long, DecimaL Single, Double |
Single | Single, Double |
Date | Date, String |
, :
Dim foo As Boolean
foo = 3
foo True . :
Dim foo As Boolean
foo =l()
VB.NET , .
. :
Option Strict Off
, .
, , l. 4.4.
4.4.
CBool Boolean
CByte Byte
CInt Integer
CIng Long
CSng Single
CDate Date
Dbl Double
CDec Decimal
CStr String
CChar Char
VB.NET , ; .
, Char ( 0 65 535), . - 2 Char CInt; Asc.
. :
Enter.
ReadLine().
, CDec (, ):
'
Option Strict On Module
Module Modulel
Sub Main()
Dim cdeg As Decimal
Console.WriteLine( Enter the degrees in centigrade...")
cdeg = CDec(Console.ReadLine())
Dim fdeg As Decimal
fdeg = (((9.0 / 5.0) * cdeg) + 32)
Console.WriteLine(cdeg & " is " & fdeg & " degrees Fahrenheit.")
Console. ReadLine()
End Sub
End Module
@ , Decimal. , !
/ VB.NET . .
|
|
VB.NET , . , : 255 , , , . .
VB.NET :
Const PIE = 3.14159 ' Option Strict
Const PIE As Double = 3.14159 ' , Math.PI :-)
, :
Const PIE_OVER_2 As Double = PIE / 2
:
Const USER_NAME As String = "Bill Gates"
Unicode 231 ( 2 !) . , :
Dim message As String
message = "Help"
() &. + , , + . $ (, aStringVariableS) .
VB.NET , String. , , , , VB.NET: VB.NET . , VB.NET StringBuilder (, ).
VB, VB.NET .
Left, Right, Mid . ., $ . 4.5 String. , (, Mid ) StringBuilder. , .
.NET String, .NET Framework. . 3.6.
4.5.
Asc
Chr Unicode
Filter ; ,
GetChar Char. 1. , GetChar("Hello",2) Char
InStr
InStrRev
Join
LCase
Left
Len
LTrim
Mid
Replace
Right
RTrim
Space ,
Split (, )
Str
StrComp
StrConv (, )
String ,
Trim
UCase
3.6. .NET Framework
/
Chars ,
Compare
Copy
Copy To ,
Empty ,
EndsWith ,
IndexOf
Insert ,
Join
LastlndexOf
Length
PadLeft .
PadRight .
Remove ,
Replace
Split ,
Starts With ,
Substring ,
ToCharArray
ToLower ,
ToUpper ,
Trim , Unicode,
TrimEnd , Unicode,
TrimStart , Unicode,
.NET Framework , 0.
.NET Framework , . :
Sub Main()
Dim river As String =" Mississippi Missippi"
'
Console. WriteLine(river. Tollpper ())
Console.WriteLine(river.ToLower())
Console.WriteLine(river.Trim())
Console. WriteLine(river. EndsWith("I"))
Console.WriteLine(river.EndsWith("i"))
Console.WriteLine(river.IndexOf("s"))
' 0!
Console.WriteLine(river.Insert(9. " river"))
'
' 0!
Console.ReadLine()
End Sub
:
MISSISSIPPI MISSIPPI
mississippi missippi
Mississippi Missippi
False
True
3
Mississi riverppi Missippi