Basically in C++ they tried to reduce the usage of preprocesor . In C Its necessary to use the preprocessor statements. All the preprocessor start with thye #. SOME OF THE PREPROC STATEMENTS are #define #elif #else #endif #error #if #ifdef #ifndef #include #line #pragma #undef #define ias generally a replacement of any thing which [...]
Programming
C++ Program : Preprocessor Compilation Linking
A C++ program has following structure // preprocesssor directives //global declarations // functn prototypes // class declartions ( may be in .h header files) int Main( int argc, char * argv[]) { //body of main } void function() { /// any func definitions } Preprocessor : Before actual compilation of C++ source code starts, preprocessor [...]
Windows Programming and windows procedure
In old DOS based c programming, we have a program or set of instructions executing in sequential manner. Windows programming is more event based. Applications do the initialization draws windows (for user input) and runs in loop to process the Event sent by operating System. So when we have any event in computer system, typically [...]
Introduction to Windows process
Every application executing on Windows is a process. Process is running instace of program. It has two components Kernel Object and Address space. Kernel object is being used by OS to manage the process and it has various statistical information about the Process. So using kernel object one can manipulate the process. The process address [...]
C, C++ entry point function main
For every C, C++ Program there is a entry point function, where program execution starts. Essentially Operating system looks for this function fro where program can be executed. This entry function is ” main” Default code looks like given below int main ( int argc, char *argv[]) { return 0; } So this function returns [...]
CObject : Top MFC base class
CObject is the topmost base class of Microsot Foundation Classes ( MFC). Most of the classes in MFC are derived from CObject class. CObject class provides following functionality. 1. Dignostic support : This is used for debugging and troubleshooting purpose. Such as dumping the contents of Object. 2. Runtime class Identification : Knowing the [...]
MFC Programming
Microsoft Foundation Classes or MFC is the wrapper classes around Win32 API’s. Essentially they provide the Windows programming in Object oriented ways. They themselves don’t provide any windows functionality but they facilitate the programmers to do windows programming with an ease and rapid development. Somehow windows programing using API are tedious and time consuming. MFC provide [...]
PHP Test : What is the difference between mysql_pconnect() and mysql_connect()
(1) mysql_connect() returns NULL on failure (2) mysql_pconnect() has a timeout period (3) If a connection is already existing, mysql_pconnect() would return that. There is no way mysql_connect() can be made to do that (4) The connection initiated by mysql_pconnect() will not be closed when the execution of the script ends
Comparison between C++ structure C++ class
C++ Structure : 1. C++ structure can have Data member and function members as well ( C structure doesn’t have function members) 2. C++ Structure can have access specifier. default access is Public 3. C++ Structure Can be inherited just like the classes. C++ Classes : 1. C++ Class can have Data member and function [...]
MFC Win32 COM Windows Programming Questions
What is the base class for MFC Framework ? CObject 2. If i derive a new class from CObject what are the basic features my derived wil get ? Runtime class identification/ dynamic object creation (b) Synchronization (c) diagnostic support. 3. What is the use of CCmdTarget ? Command routing 4. What is document-view architecture [...]
Global/Static variables and external/internal linkage
In C/C++ variables can be of type global, static, local/auto and register type. The linkage is useful to know relation between lifetime and the scope or the accessibility of the variable at particular place.During the program compilation they are linked( to the other part of program) in two ways, External or internal linkage. External linkage [...]
