Conceptually, compilers synthesize a default constructor for every class or struct, unless a constructor was already defined by the user. However, in certain conditions (a simple data struct, for example),

It’s possible to create mailto links that include a subject line in addition to just the recipient’s e-mail address, however, not all e-mail programs support this functionality. That said, to

A garbage collector is handy, since it eliminates a big source for bugs, runtime crashes and memory leaks. However, garbage collection is not for free; it incurs additional runtime overhead

Polymorphism is the ability of different objects to react in an individual manner to the same message. This notion was imported from natural languages. For example, the verb “to close”

Question: Is it possible to rename a login? Answer: Sorry, no. You must drop the login and then create a new one with the corrected name.

Question: My database and log keep filling up and I can’t truncate the log. Any suggestions? Answer: There are two methods to empty the transaction log. One can regularly dump

According to the C++ Standard, you are still allowed to apply operator ++ to a variable of type bool for backward compatibility with old code. However, this practice is deprecated

Some users consider the addition of namespaces to C++ as superfluous or even harmful. In order to understand why namespaces were added to the language, imagine that the file system

You can provide Print Preview at different scales. First, make your printing routine take on the object it should draw as a parameter. Then, for printing, pass the routine the

This method is handy when the user enters data that you need to validate against a lookup table. Validating the value by querying the database is out of the question

Suppose you have a database field that returns a date in the Short Date format. Neither a numeric sort nor a string sort would order this column correctly. To sort

The tip “Color Status Indicator” [“101 Tech Tips for VB Developers,” Supplement to the February 1997 issue of VBPJ, page 26] got me thinking that it would look even more

When developing relational database applications, you often need to use list boxes or combo boxes to store records with alphanumeric keys. You can load numeric keys into the ItemData array

To add user-defined properties to controls, use this code to store them in the control’s tag. You can define multiple additional properties at design or run time. You can easily

The placement-new operator constructs an object on a pre-allocated buffer. The pre-allocated buffer has to be allocated on the heap. char *pbuff = new char[1024]; // heap allocation using plain

The Standard Template Library (STL) is a collection of generic algorithms and containers. It provides a new approach in software development, namely, generic programming. How does generic programming differ from

A unique name of an identifier consists of its namespaces(s), each followed by scope resolution operator, then its class name, and finally the variable itself. Since both namespaces and classes

In order to block creation of class instances, you can declare its constructor as protected. class CommonRoot { protected: CommonRoot(){}//no objects of this class can be instantiated};class Derived: public CommonRoot

The WhatsThisButton property returns or sets a value that determines whether the WhatsThisButton appears in the title bar of a Form object during run time. For the WhatsThisButton to appear

If you want to print text on an object with 3-D effects, use this subroutine to convert fonts into 3-D fonts with borders. In this routine, the user can define

Use the built-in AppActivate command to switch to another application easily if you know its title. You can even close the application programmatically: ‘This will close appPrivate Sub CloseApp (AppTitle

By default, the right-click functionality needed for What’s This? Help is not available in VB. Selecting a menu command from a context menu created for the button lets you display

Question: We have an ASP application that queries a database and returns the data to formatted pages. The user would also like the data returned in a .CSV format for

Question: I have a Web site that forces a login with NT security. (Thus the person has to have an NT account to login.) I want to include a logoff

Question: What are the big differences between the March pre-release beta and the final release of Visual Interdev? Regards,Brooks Martin Answer: I suppose the biggest difference is that the March

Sometimes it is useful to keep track of users’ file download activity on your site. When a user clicks on a hyperlink to download a file, you can run an

In some frameworks (MFC, for instance), it’s customary to add the scope resolution operator :: before a global function’s name to mark it explicitly as a function that is not

The Graphics.create() method is a convenient way of creating a copy of a Graphics context. For example, you can use the Graphics.create() method if you want to make a copy

Assume you want a text control with a vertical scrollbar, but you don’t want users to be able to modify it and you don’t want users to see any caret