Rediger

Del via


Data Type Conversions

Each programming language defines certain types and containers for data. Most of these data types, especially the primitives, map easily to other programming languages. Some data types, however, have no equivalent in another language and cannot be converted.

For specific information about data types not recognized by your programming language, see the following topics:

The following table lists conversions between programming languages for common data types.

C++ Visual Basic Java Contains
signed char
Not supported
byte
1-byte signed integer
(VT_I1, [T])
unsigned char
Byte
Not supported
1-byte unsigned integer
(VT_UI1, [V][T][P][S])
unsigned char
Character
char
2-byte Unicode character
(VT_UI2, [T][P])
short
Integer
short
2-byte signed integer
(VT_I2, [V][T][P][S])
unsigned short
Not supported
Not supported
2-byte unsigned integer
(VT_UI2, [T][P])
int
Long
int
4-byte signed integer
(VT_I4, [V][T][P][S])
unsigned int
Not supported
Not supported
4-byte unsigned integer
(VT_UI4, [T][P])
__int64
Not supported
long
8-byte signed integer
(VT_I8, [T][P])
unsigned __int64
Not supported
Not supported
8-byte unsigned integer
(VT_UI8, [T][P])
float
Single
float
4-byte floating-point number
(VT_R4, [V][T][P][S])
double
Double
double
8-byte floating-point number
(VT_R8, [V][T][P][S])
BSTR
String
java.lang.String
Automation string
(VT_BSTR, [V][T][P][S])
BOOL
Boolean
boolean
Boolean
(VT_BOOL, [V][T][P][S])
VARIANT
Variant
com.ms.com.Variant
VARIANT FAR*
(VT_VARIANT, [V][T][P][S])
IUnknown
object
com.ms.com.IUnknown
IDispatch interface pointer
(VT_DISPATCH, [V][T][P][S])
DATE
Date
com.ms.com.Variant
Date
(VT_DATE, [V][T][P][S])
CURRENCY
Currency
com.ms.com.Variant
Currency
(VT_CY, [V][T][P][S] or VT_DECIMAL, [V][T][S])

For information about VARTYPE values and how to use them, see the topic IDispatch Data Types and Structures.

The data type conversions between scripting languages are simpler than those for programming languages. JScript and JavaScript both support the same data types, and VBScript supports only a single data type, Variant. Thus, all JScript and JavaScript data types become Variant types when converted to VBScript. When you convert VBScript to JScript or JavaScript, the Variant types become numbers, strings, Boolean values, and so on.