Question: Can I instantiate an abstract class? Answer: No, you cannot instantiate an abstract class. However, you can declare a pointer or a reference to it: class Abs{public: virtual void

You should always use Option Explicit statement in your .asp file. Thisstatement will enforce that you explicitly declare all the variables in thescript. The whole problem: VBScript allows you to

You should always prefer to use Local variables. Local variables reside within functions and subs. They have local scope and limited lifetime. These variables are compiled into numeric references and

Here is a simple way by which you can display a greeting message to a user at the time of login.There are certain scenarios where you can use thisfeature to

The type that a template takes as an argument must have external linkage. This means that you cannot instantiate a template with a locally-declared type: int main(){ struct S {

A function’s signature consists of the function’s parameter list and the parameters’ ordering. A member function’s signature also includes the const/volatile qualifiers (if any) of that function. Signatures provide the

Question: How can I determine the maximum size of an INPUT field? Answer: Although you can certainly use JavaScript to find out the size of your user’s screen or the

Question: How can I create a “browse” facility in my application&#151something which throws up a dialog box that allows the user to view folders and select one, as in Microsoft

Question: I have Exchange 5.0 running on a server that has become too small to do everything asked of it. I bought Exchange 5.5 Upgrade and a totally new copy

Question: I’m trying to declare some data for an object such that, when necessary, other functions can use the object not only to perform member functions but also serve as

Question: Is there a maximum URL length? One of my forms has a bunch of text fields on it so I am concerned that it might truncate when I pass

Question: Is there is a way to create a text field that only accepts numeric input? Answer: There are probably a couple of a ways to go about doing this.

Question: How can I prevent certain files on my site from being bookmarked? Answer: There is no way to fully prevent people from bookmarking a certain URL on your site.

Question: I have var1 and var2 both ints in a DB (only ints will be entered into var1, var2). But I want the result to show answer with decimal places:

Question: I have a table with a text field that stores a long description. When I use the Select statement to query the table, it only returns 255 characters. How

Question: When I try to do a simple insert in a table with 25,000 records, it takes a long time do execute. In the same database for a table with

Question: When I execute this query: create table #T1 ( pk numeric( 9 ) ) drop table #T1 create table #T1 ( pk numeric( 9 ) ) drop table #T1

Question: I have an HTML page that is broken up into two different frames. The left frame acts as a navigation tool. The right frame is the user interface, which

Question: I have produced a bunch of DHTML library functions that work in a cross-platform environment, down to the point of redefining the layer object in Netscape and writing customized

Question: When I define a window “in desktop” with the main Visual FoxPro window hidden, I can’t get it to show up using Show Window or Activate Window while the

Question: I want to output a report by Visual FoxPro 6.0 and fax it by WinFax Pro 9.0. I can output my report to an ASCII file which is then

Question: I am inserting some text into a DIV in Netscape using the .open, write(), and close() methods. At first there is nothing in the DIV, and when I check

If you fully understand how VB and VBA work, you can often save some statements. This makes your listings more concise and more readable, and indirectly optimizes your program. Here

Let’s assume you must test whether the most significan bit of an integer value is set or not. This is the code that you usually write: ‘ two cases, depending

You can often use the Instr function in an unorthodox way to write more concise code. A typical example is when you need to test a single character: ‘ test

Use IIf when setting a value based upon an expression. This works only in situations where you have two choices, based upon the result of a Boolean expression. ‘long wayIf

When setting a Boolean value based upon the result of an expression, avoid using an unnecessary If/Then/Else structure. ‘Instead of using this lengthy syntax . . .If SomeVar > SomeOtherVar

Many VB developers don’t realize that the Switch built-in function can often save a lot of code. This function takes any number of (expr, value) pairs, it evaluates all expressions

The Choose function lets you often make more concise, albeit not faster, code, because it lets you replace a lengthy Select Case block. For example, the following code: Select Case