C++ Notes

VARIABLES
variables must be:
declared (the type of variable)
defined (values assigned to a variable)
before it can be used in a program.

DATA TYPES
C++ supports the following inbuilt data types:-
int (to store integer values),
float (to store decimal values),
char (to store characters),
bool (to store Boolean value either 0 or 1) and
void (signifies absence of information).

KEYWORDS
reserved wordsjavascript:void(0)

IDENTIFIERS
name of functions, variables, classes, arrays etc.

CONSTANTS
fixed values which cannot change.

Layered Web Applications with ASP.NET

In the diagram in figure 1 you see a process go around in a counter clockwise direction. The process goes through the following 6 steps:

1. The Presentation layer asks the BLL for some object, for example a contact person.


2. The BLL can optionally perform some validation (for example, is the current user allowed to make this call?) and then forwards the request to the DAL.


3. The DAL connects to the database and asks it for a specific record.


4. When the record is found, it is returned from the database to the DAL.


5. The DAL wraps the database data in a custom object and returns it to the BLL.


6. Finally, the BLL returns the object to the Presentation layer, where it could be displayed on a web page for example.