Question: Can I pass the address of a PowerBuilder function as an argument to an external function located in a dll? The dll documentation shows that it expects the address

Question: How can I support 64-bit integers on a 32-bit system? I need to do division on numbers exceeding 4.3 billion. I have the resaults in a char value, and

Question: Assume that you have a class Distance and two objects dist1 and dist2. You have initialized the object dist1. Now you do: Distance dist2(dist1) to create a copy of

Question: I am teaching an introductory C++ course at thehigh school level. My textbook briefly coversdata files–sequential access–but doesn’t provide many examples of how to write/read multiple variables. Where would

Question: How do I convert a DOS file into a Windows program? Answer: Unfortunately, not very easily. While DOS programs will run under Windows and you may also want to

Question: int num = 50;int **stuff;stuff = new int* [num];for (int i = 0 ; i < num ; ++i) stuff[i] = new int [num]; The code above is copied

Question: Functions are inherited easily. But if you have a variable in the base class and you want have the same variable but with a different type in the derived

Question: How does one go about disabling/enabling buttons and check boxes in dialogs based on the state of other buttons or check boxes? The controls in question are of the

Question: I was trying to do some direct memory stuff (writing to the DOS console buffer or a graphics screen) using my Visual C++ compiler. Unfortunately, the compiler is telling

Question: I would like to know what is the difference in C between opening a file opened in binary or text mode. Answer: The primary difference is in the handling

Question: I am creating a Windows app using CC++. I have been using a shareware C compiler and a shareware resource compiler. I have compiled my .rc file into a

Question: In VB, how do you rename a file (at runtime)? Answer: Use the FileSystem object (Microsoft Scripting Runtime, SCRRUN.dll) as follows: Dim fs As New FileSystemObjectDim f As FileSet

Using a text box and submit button, you can validate an e-mail address to make sure there is only one @ sign and that it is not at the beginning

On some occasions, the performance boost that can result from moving declarations is quite considerable. Consider this example: void use() { string s1; if (condition == false){ return; //s1 was

Java’s PipedInputStream and PipedOutputStream classes allow you to write data to an OutputStream object and to read this data from an InputStream object (see the tips “Pass Data Between Threads

Web authors should be used to using the ALT tag to provide a textual label for an image. However, you can’t apply ALT text to a textual link, and most

Objects are made serializable by implementing the java.io.Serializable interface. In general, when you serialize an object instance, all of the instance’s fields are considered to be part of its state,

A downcast is a cast from a base to a derived object. Before the introduction of RTTI to the language, downcasts were regarded as bad programming practice–they were unsafe and

A compiler can automatically optimize the code by unrolling loops. Consider this code: int *buff = new int[3]; for (int i =0; i

You may have used the tag to include ActiveX controls on your Web pages, but did you know that the tag can be used to include many other types of

When you create the visual components that make up a user interface, their size and position are usually constant. However, it’s sometimes necessary to change a component’s size or position

Question: I have two drop-down menus. How do I set a validation on my page so that users cannot go all the way to the server if they don’t select

Question: I have a page with two drop-downs and two corresponding radio buttons. When I choose an item from one drop-down, I’d like the corresponding radio button to become checked.

Question: I built a Web site for my company using FrontPage 98 and can not seem to upload it back to the Internet. I get error messages about server extensions.

VB5 provides interface inheritance through the use of the Implements keyword. For example, CFullTimeEmployee can implement the IEmployee interface. This interface might include basic information such as name, social security

Here’s a demo for using a Label control as a splitter between two controls, as well as sample code for employing the splitter in an Explorer-like application: Option ExplicitPrivate mbResizing

Select Case statements can lead to errors when the test expression in the Select Case line doesn’t yield a true result for any of its individual Case expressions. Therefore, you

Consider these two examples of code that add a string to a textbox. Example 1: Text1.text = Text1.text & MyString Text1.SelStart = Len(Text1.text) Example 2: Text1.SelStart = Len(Text1.text) Text1.SelText =

VB6 comes with an ActiveX control named MSWLESS.ocx (“Microsoft Windowless Controls 6.0”), which contains lightweight equivalents for these standard controls: WLTextWLFrameWLCommandWLCheckWLOptionWLComboWLListWLHScrollWHVScroll The controls have lower resource consumption than their regular

You’ll use the Format function most often with numbers, but it can be useful when applied to strings as well. For example, you can format a credit card number-which is