أنواع البيانات تشير إلى نظام واسع يستخدم لإعلان المتغيرات أو وظائف من أنواع مختلفة. يحدد نوع المتغير مقدار المساحة التي يشغلها في التخزين
انواع البيانات المتاحة فى الفيجوال بيسك دوت نت
يوفر VB.Net مجموعة واسعة من أنواع البيانات. ويبين الجدول التالي جميع أنواع البيانات المتاحة:
| نوع البيانات | التخزين | مدى قيمةالمتغير |
|---|---|---|
| Boolean | Depends on implementing platform | True or False |
| Byte | 1 byte | 0 through 255 (unsigned) |
| Char | 2 bytes | 0 through 65535 (unsigned) |
| Date | 8 bytes | 0:00:00 (midnight) on January 1, 0001 through 11:59:59 PM on December 31, 9999 |
| Decimal | 16 bytes | 0 through +/-79,228,162,514,264,337,593,543,950,335 (+/-7.9...E+28) with no decimal point; 0 through +/-7.9228162514264337593543950335 with 28 places to the right of the decimal |
| Double | 8 bytes |
-1.79769313486231570E+308 through -4.94065645841246544E-324, for negative values
4.94065645841246544E-324 through 1.79769313486231570E+308, for positive values
|
| Integer | 4 bytes | -2,147,483,648 through 2,147,483,647 (signed) |
| Long | 8 bytes | -9,223,372,036,854,775,808 through 9,223,372,036,854,775,807(signed) |
| Object |
4 bytes on 32-bit platform
8 bytes on 64-bit platform
| Any type can be stored in a variable of type Object |
| SByte | 1 byte | -128 through 127 (signed) |
| Short | 2 bytes | -32,768 through 32,767 (signed) |
| Single | 4 bytes |
-3.4028235E+38 through -1.401298E-45 for negative values;
1.401298E-45 through 3.4028235E+38 for positive values
|
| String | Depends on implementing platform | 0 to approximately 2 billion Unicode characters |
| UInteger | 4 bytes | 0 through 4,294,967,295 (unsigned) |
| ULong | 8 bytes | 0 through 18,446,744,073,709,551,615 (unsigned) |
| User-Defined | Depends on implementing platform | Each member of the structure has a range determined by its data type and independent of the ranges of the other members |
| UShort | 2 bytes | 0 through 65,535 (unsigned) |
وظائف تحويل النوع في VB.Net
يوفر VB.Net الوظائف التالية في تحويل نوع الخط:
| S.N | Functions & Description |
|---|---|
| 1 |
CBool
Converts the expression to Boolean data type.
|
2
|
CByte
Converts the expression to Byte data type.
|
3
|
CChar
Converts the expression to Char data type.
|
4
|
CDate
Converts the expression to Date data type
|
5
|
CDbl
Converts the expression to Double data type.
|
6
|
CDec
Converts the expression to Decimal data type.
|
7
|
CInt
Converts the expression to Integer data type.
|
8
|
CLng
Converts the expression to Long data type.
|
9
|
CObj
Converts the expression to Object type.
|
10
|
CSByte
Converts the expression to SByte data type.
|
11
|
CShort
Converts the expression to Short data type.
|
12
|
CSng
Converts the expression to Single data type.
|
13
|
CStr
Converts the expression to String data type.
|
14
|
CUInt
Converts the expression to UInt data type.
|
15
|
CULng
Converts the expression to ULng data type.
|
16
|
CUShort
Converts the expression to UShort data type.
|
مثال للتحويل بين انواع البيانات
التصريح عن متغير رقمى
Dim n As Integer
تحويل المتغير للنوع char
CChar(CStr(n)))
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