Object Oriented Programming: Part 3

History of C++

C++ is extension of C language and was developed by Bjarne Stroustrup in 1983 at Bell labs. Dennis Ritche developed C language at Bell labs in 1972. C language was a direct descendant of the language 'B', which was developed by Ken Thompson as a system programming language for Unix at Bell labs in 1970. 'B' language descended from the language 'BCPL' that was designed in 1967 by Martin Richards in Cambridge University. This language was easier to understand by 'CPL'. 'BCPL' (Basic Combined Programming Language) language descended from the language named 'CPL' (Combined Programming Language) which was developed at Cambridge University in 1963. 'CPL' language was big with lots of features but it was very difficult to implement. 'CPL' was direct descendent from a basic language known as 'Algol 60', which was designed by an International Committee in 1960.

Advantages of C++

Although C++ has long list of advantages but here are some major advantages listed:

• C++ allows expression of abstract ideas. As C++ is third generation language, that allow the programmers to express their ideas at a high level as compared to assembly languages.
• C++ still allow the programmers to keep low-level control, even C++ is third generation language but it has some feels like assembly languages because it allows the programmers to get down too in the low-level workings. C++ also allows the programmers to keep strict control over memory management.
• C++ has national standard (ANSI) and it is easily integrated with pre-existing code. It also allows the programmers to reuse common libraries, so certain common functions do not need to be written more than once.
• C++ is reusable and object-oriented so it allow to reuse the codes through inheritance.
• C++ is widely used and taught. It is used in large world community.

Simple Hello Program

Given below is simple C++ program, which will print 'Hello' on the screen:

          #include<iostream.h>

          #include<conio.h>

          int main()

          {

                    cout<<"Hello";

                    return 0;

                    getch();

          }

Identifiers (Keywords)

Keywords (Identifiers) are the word whose meaning is already been explained to C++ compiler. The keywords cannot be used as variable names because if we do so, means we are trying to assign a new meaning to the keyword, which is not allowed by the computer. For example: auto, int, struct, extern, if, do, for, float etc.

Note: Continue in next part.

HAVE A HAPPY CODING!