When to use variables, objects and CTYPE?

Hello
Under what conditions "must" you use "CTYPE" when working with variables and
objects?

"winlin" <winlin (AT) verizon (DOT) com> wrote

Hello
Under what conditions "must" you use "CTYPE" when working with variables
and
objects?

Can you provide some sort of contextual information on what you want to do
that you believe needs ctype?
Normally, if I need to make a specific conversion that requires "forcing, I
use explicit_cast<type>(argument).

You must use CType when your code has the OPTION STRICT ON either in the
project properties or in the VB Code itself and when the conversion is a
narrowing one.

For instance, you can always write: Dim i as Integer
Dim d as Double = i
But if you have set "Option strict On" in the project properties or in the
code, Dim d as Double

Dim i as Integer = d will not
compile,

you have to write: Dim d as Double

Dim i as Integer = CType(d, double)
(it's a way to tell the compiler that you know what you are
doing)
For objects, if Customer Inherits from Person, you can always write: Dim C
as new Customer

Dim P as Person = C
But with Option Strict On, if you write Dim C as new Customer
Dim P as Person =
C
Dim D as Customer
= P, the compiler will not accept the last statement
it will accept: Dim C as new Customer
Dim P as Persomn = C
Dim D as Customer = CType(P, Customer)

I hope I am clear enough. Sometimes my students understand what I say.

Marc Biotteau, MCT

"winlin" <winlin (AT) verizon (DOT) com> wrote

Hello
Under what conditions "must" you use "CTYPE" when working with variables
and
objects?