Introduction of C++

C++ is an object oriented programming language.

What is C++?

C++ is an object oriented programming language. C++ is first object oriented programming language.

C++ was developed by Bjarne Stroustrup at AT & T's Bell Labs, USA in 1979.

Features of C++.

• C++ is a middle level language.
• C++ supports principles of object oriented paradigm.
• C++ joins three separate programming traditions.
• C++ is first object oriented programming system.

What is OOPS?

OOPS is a programming approach which revolvs around the concept of "object".
Any entity in the system that can be defined as a set of properties and set of operations performed using entity's property set, is known as object.'

• Encapsulation
• Data hiding
• Abstraction
• Polymorphism
• Inheritance

Variables

variables are the names of memory locations where we store data.
variable name is any combination of alphabet (a to z or A to Z), digit(0 to 9) and underscore (_).

Rules for naming variables in C++

• First character must be alphabet or underscore(_).
• no commas, blanks allowed
• no special symbol other than (_) allowed
• variables names are case sensitive we must create meaningful variables name in our programms.

Types of variables

• local
• global
• static

local variable

local variable can declare and defineinside function of constructor block. It cannot access outside of function block.

global variable

global variable can declare out side of function block. global variable can acces any where in program, if it is public.

static variable

static variable can declare at the class level. No need to create an object to access static variable.

Keywords

Keywords are reserved words, whose meaning is already known to the compiler.

auto	double	struct	int	asm	private
break	else	long	switch	catch	public
case	enum	register	typedef	class	protected
char	extern	return	union	delete	template
const	short	float	unsigned	friend	this
continue	signed	for	void	inline	throw
default	sizeof	goto	volatile	new	try
do	static	if	while	operator	virtual

Difference between C and C++

• c follows top down approach of programming
• c++ follows bottom up approach of programming

Comments

comments are used to clarify something about the program in plain languagqe.

There are two types of comments in C++.

• Single line comment.
• Multi line comment.