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The Latest

Do Not Use Global Variables With Recursion

Global variables should never be used with recursion. It leads to stack overflow and program crash. Recursion works well only if it is in a self contained unit, using local

Use the Correct Date Format in SQL Query

Frequently the date format is mistakenly used in a SQL query of MS ACCESS. For example, when you want to make a query get records from May 1, 2000 in

MP3 Tag Editor

A simple but effective MP3 Tag Editor written entirely in Visual Basic 6, and that consists of a DLL and a front-end application. What’s best is that you get the

Server-Side Caching in COM+ and VB

Is server-side caching good or bad? This question can create many heated discussions. Since I’m from Sweden, I like what we call the golden middle course. We even invented a

Generating Data with XSLT

t’s becoming common to retrieve data from a relational database formatted as a hierarchical XML document. By using an XML schema, it’s possible to generate data from XML documents and

Using CoInitialize()

CoInitialize() should be called for each thread in the application that makes COM calls. Not just once at application startup.

Option Explicit

Many developers code text boxes to only accept numeric values. They usually forget about keyboard and mouse copy and paste functions. The following code only allows values 1 to 9

The Paint Protocol

The AWT Component.paint and Component.update methods take a Graphics object as a parameter. This object should not be retained, because it might be a transient object valid only during the

Create a List of Months

The following code creates an array with month names or populates a combobox or listbox with same = without all the typing: holdMonth(1) =

GetAppFilename – Return the application’s file name and path

Private Declare Function GetModuleFileName Lib “kernel32” Alias _ “GetModuleFileNameA” (ByVal hModule As Long, ByVal lpFileName As String, _ ByVal nSize As Long) As LongPrivate Declare Function GetModuleHandle Lib “kernel32” Alias

SetWallPaper – Change the desktop’s wallpaper

Private Function SystemParametersInfo Lib “user32” Alias _ “SystemParametersInfoA” (ByVal uAction As Long, ByVal uParam As Long, _ ByVal lpvParam As Any, ByVal fuWinIni As Long) As LongConst SPI_SETDESKWALLPAPER = 20′

SearchFileOnPath – Search a file on system path

Private Declare Function SearchPath Lib “kernel32” Alias “SearchPathA” (ByVal _ lpPath As String, ByVal lpFileName As String, ByVal lpExtension As String, _ ByVal nBufferLength As Long, ByVal lpBuffer As String,

Misuse of System.exit

The System.exit method forces termination of all threads in the Java virtual machine. This can be drastic. It might, for example, destroy all windows created by the interpreter without giving

How to Prevent a Class From Serialization

The following code prevents classes from serialization: public class MyClass implements Serializable{//you can write your code hereprivate void writeObject(ObjectOutputStream out) throws IOException{ throw new NotSerializableException();}private Object readObject(ObjectInputStream in) throws IOException,ClassNotFoundException{

Examine the Number of Extents in a Table

The amount of time it takes to retrieve data blocks is proportionate to the number of extents in the table. Ideally, a table should have one to three extents. Run

Customizing JFileChooser

The class JFileChooser inside javax.swing.* can be customized to display your own labels using the UIManager.put() method. It is a static method that takes an Object key (Original value) and

Eliminating Duplicate Values

To eliminate duplicate values in a collection, Java provides it own API. HashSet (java.util.*) is the class which implements Set interface. import java.util.*;class Duplicate{ static void main(String[]arr){ HashSet set=new HashSet();

“Shrink” the Size of a File

Visual Basic lacks the ability to make a file smaller without having to recreate it. But it is possible to use the SetEndOfFile API. Here is a function for it:

Generic Name Property Procedure with TypeName

One easy way to implement a generic name property of a class is to make a property procedure with TypeName function. Public Property Get Name() As String Name = TypeName(Me)End

A Super-Efficient Toggle Case Using XOR

My benchmarking shows that ToggleCase can crunch through a 2,000,000character string in under 4 seconds on a Pentium II. Public Function ToggleCase(ByVal strData As String) As String ‘This technique gets

Warnings Regarding Temporaries and Their Meaning

The following code causes a somewhat cryptic warning message: struct Employee{ long ID; string name;};Employee emp;void func(int& id) { id=0;}// warning below issued for the following call:func(emp.ID);

Right-Justification of Output

To right justify the output of cout, call the width() function with the size of the output screen (in characters) as an argument. In the following example, the program calls

What You Should Include in a Header File

A header file should begin and end with #include guards to guarantee that it’s not #included more than once during the same compilation session. A typical #include guard looks as