Backslash Character Constants in C:

o There are some characters which have special meaning in C language.

o They should be preceded by backslash symbol to make use of special function of them. o Given below is the list of special characters and their purpose.

C++

C++ is a middle-level programming language developed by Bjarne Stroustrup starting in 1979 at Bell Labs. C++ runs on a variety of platforms, such as Windows, Mac OS, and the various versions of UNIX.

Overview

C++ is a statically typed, compiled, general-purpose, case-sensitive, free-form programming language that supports procedural, object-oriented, and generic programming.

C++ is regarded as a middle-level language, as it comprises a combination of both high-level and low-level language features.

C++ was developed by Bjarne Stroustrup starting in 1979 at Bell Labs in Murray Hill, New Jersey, as an enhancement to the C language and originally named C with Classes but later it was renamed C++ in 1983.

C++ is a superset of C, and that virtually any legal C program is a legal C++ program.

Note: A programming language is said to use static typing when type checking is performed during compile-time as opposed

to run-time.

Object-Oriented Programming

C++ fully supports object-oriented programming, including the four pillars of object-oriented development:

Standard Libraries

Standard C++ consists of three important parts:

brary giving a rich set of functions manipulating files, strings, etc.

Use of C++

C++ is used by hundreds of thousands of programmers in essentially every application domain.

C++ is being highly used to write device drivers and other softwares that rely on direct manipulation of hardware under realtime constraints.

C++ is widely used for teaching and research because it is clean enough for successful teaching of basic concepts.

Anyone who has used either an Apple Macintosh or a PC running Windows has indirectly used C++ because the primary user interfaces of these systems are written in C++

C++ Basic Syntax

When we consider a C++ program, it can be defined as a collection of objects that communicate via invoking each other's methods. Let us now briefly look into what do class, object, methods and instant variables mean.

Object - Objects have states and behaviors. Example: A dog has states - color, name, breed as well as behaviors -

wagging, barking, eating. An object is an instance of a class.

Class - A class can be defined as a template/blueprint that describes the behaviors/states that object of its type support. Methods - A method is basically a behavior. A class can contain many methods. It is in methods where the logics are

written, data is manipulated and all the actions are executed.

Instant Variables - Each object has its unique set of instant variables. An object's state is created by the values assigned

to these instant variables.

C++ Program Structure:

Let us look at a simple code that would print the words Hello World. #include<iostream>

// main() is where program execution begins. int main()

{

cout <<"Hello World";// prints Hello World return0;

}

Let us look various parts of the above program: For this program, the header <iostream> is needed.

using namespace std; tells the compiler to use the std namespace. Namespaces are a relatively recent addition to

C++.

// main() is where program execution begins. is a single-line comment available in C++. Single-line

comments begin with // and stop at the end of the line.

int main() is the main function where program execution begins.

cout << "This is my first C++ program."; causes the message "This is my first C++ program" to be

displayed on the screen.

return 0; terminates main( )function and causes it to return the value 0 to the calling process. C++ Identifiers:

A C++ identifier is a name used to identify a variable, function, class, module, or any other user-defined item. An identifier starts with a letter A to Z or a to z or an underscore (_) followed by zero or more letters, underscores, and digits (0 to 9). C++ does not allow punctuation characters such as @, $, and % within identifiers. C++ is a case-sensitive programming language. Thus, Manpower and manpower are two different identifiers in C++.

Here are some examples of acceptable identifiers: Mohd zara abc move_ name a_123

myname50 _temp j a23b9 retVal

C++ Keywords:

The following list shows the reserved words in C++. These reserved words may not be used as constant or variable or any other identifier names

Asm else new this

Auto enum operator throw

Bool explicit private true

Break export protected try

Case extern public typedef

Catch false register typeid

Char float reinterpret_cast typename

Class for return union

Const friend short unsigned

const_cast goto signed using

continue If sizeof virtual

Default inline Static void

Delete int static_cast volatile

Do long Struct wchar_t

Double mutable Switch while

A digital system can understand positional number system only where there are only a few symbols called dig its and these symbols represent different values depending on the position they occupy in the number.

A value of each dig it in a number can be determined using The digit

The position of the dig it in the number

The base of the number system (where base is defined as the total number of dig its available in the number system).

Decimal Number System

The number system that we use in our day-to-day life is the decimal number system. Decimal number system has base 10 as it uses 10 dig its from 0 to 9. In decimal number system, the successive positions to the left of the decimal point represent units, tens, hundreds, thousands and so on.

Each position represents a specific power of the base (10). For example, the decimal number 1234 consists of the dig it 4 in the units position, 3 in the tens position, 2 in the hundreds position, and 1 in the thousands position, and its value can be written as

(1x1000)+ (2x100)+ (3x10)+ (4xl) 1000 + 200 + 30 + 1

1234

As a computer programmer or an IT professional, you should understand the following number systems which are frequently used in computers.

Binary Number System

Characteristics

Uses two dig its, 0 and 1.

Also called base 2 number system

Each position in a binary number represents a 0 power of the base (2). Example 20

Last position in a binary number represents a x power of the base (2). Example 2x where x represents the last position - 1.

Example

Binary Number: 101012

Octal Number System

Characteristics

Uses eig ht dig its, 0,1,2,3,4,5,6,7. Also called base 8 number system

Each position in a octal number represents a 0 power of the base (8). Example 80

Last position in a octal number represents a x power of the base (8). Example 8x where x represents the last position - 1.

Example

Octal Number: 125708

Calculating Decimal Equivalent

Hexadecimal Number System

Characteristics

Uses 10 dig its and 6 letters, 0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F.

Letters represents numbers starting from 10. A = 10. B = 11, C = 12, D = 13, E = 14, F = 15. Also called base 16 number system

Each position in a hexadecimal number represents a 0 power of the base (16). Example 160

Last position in a hexadecimal number represents a x power of the base (16). Example 16x where x represents the last position - 1.

Example

Hexadecimal Number: 19FDE16 Calculating Decimal Equivalent: