A Hashmap is often used to store Keyword-Value pairs. The keywords are strings, so it is convenient to return a list of the keywords as an array of Strings. Fortunately,

I have very simple way to do this with just one line of code. Place the following line in the proper position, often the first line in LostFocus event (assuming

In the same scope, it’s not possible to have different values for default arguments. For example, this would be an error: void foo(int i = 0){ cout

Here is an example: class Shape {public: Shape() { }; virtual void draw() {};};class Circle : public Shape {private: int m_iRadius;public: Circle(int iRadius){ m_iRadius = iRadius; } virtual void draw()

Static data members must be explicitly defined exclusively in one source file. Here’s an example of a header file, such as MyClass.h: class MyClass { public: static int x; //

The ++ operator can be used in prefix and postfix. When it is used as a preifx , its value is evaluated first, then the statement is executed. For example:

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

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

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

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 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

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

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

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′

Private Declare Function FormatMessage Lib “kernel32” Alias “FormatMessageA” _ (ByVal dwFlags As Long, lpSource As Any, ByVal dwMessageId As Long, _ ByVal dwLanguageId As Long, ByVal lpBuffer As String, ByVal

‘ Create a nested directory” This is similar to the MkDir command, but it creates any’ intermediate directory if necessarySub MakeDirPath(dirname As String) Dim i As Long, path As String

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,

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

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{

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

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

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();

This tip clarifies the meaning of

You may find that you want to know something about the form that contains the control you wish to use. You could do this by passing a reference to the

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:

The following recursive function allows users to do an expand all via apopup menu: Public Sub ExpandAll(ByVal aNode As Node) Dim l_Counter As Long Dim l_Children As Long Dim temp_Node