|
VBScript supports many standard functions, these include:
[Functions]
In VBScript there is only one data type: Variant. This type
can contain several different types of information, such as
strings, or numeric values. It is this type that is returned
by all the functions using in VBScript. As much as possible
VBScript assumes the data type that is be-ing used. For example
if it is a numeric operation it will assume that the values
are numeric, whereas a string search function would assume
the values were strings. Strings, though, can always be defined
within quotation marks.
In addition to variant, there are several subtypes, which
can be used to convert from one representation to another,
these are:
Empty.
This is were the variant is uninitialized. In a numeric value
it will be set to zero, in a string format it will be a Null
string.
Null.
No valid data.
Boolean.
This contains a True or False.
Byte.
This contains an integer in the range 0 to 255.
Integer.
This contains an integer in the range -32,768 to 32,767.
Currency.
This contains a range from-922,337,203,685,477.5808 to 922,337,203,685,477.
5807.
Long.
This contains an integer in the range -2,147,483,648 to 2,147,483,647.
Single.
This contains a single-precision, floating-point number in
the range -3.402823E38 to -1.401298E-45 for negative values;
1.401298E-45 to 3.402823E38 for positive values.
Double.
This contains a double-precision, floating-point number in
the range -1.79769313486232E308 to -4.94065645841247E-324
for negative values; 4.94065645841247E-324 to 1.79769313486232E308
for positive values.
Date.
This contains a number that represents a date between January
1, 100 to Decem-ber 31, 9999.
String.
This contains a variable-length string that can be up to approximately
2 billion characters in length.
Error.
This contains an error number.
There are several functions which can be used to convert
from one format to another. These include:
CBool Convert expression to a Variant of subtype Boolean.
CByte Convert expression to a Variant
of subtype Byte.
CCur Convert expression to a Variant
of subtype Currency.
CDate Convert expression to a Variant
of subtype Date.
CDbl Convert expression to a Variant
of subtype Double.
CInt Convert expression to a Variant
of subtype Integer.
CLng Convert expression to a Variant
of subtype Long.
CSng Convert expression to a Variant
of subtype Single.
CStr Convert expression to a Variant
of subtype String.
ASP example
|
|
<%
val1 = 10
val2 = 20
result = Cstr(val1) + Cstr(val2)
response.write "<BR>Value is " &
result
result = val1 + val2
response.write "<BR>Value is " &
result
%>
|
Executed code
|
|
Value is 1020
Value is 30
|
where it can be seen that the first operation has converted
the values into strings and then implemented a string concatenate
function, while the second version has implemented an arithmetic
addition.
|