C++ is a general-purpose programming language. It has imperative, objectoriented
and generic programming features, while also providing facilities for lowlevel
memory manipulation. It was designed with a bias toward system
programming and embedded, resource-constrained and large systems, with
performance, efficiency and flexibility of use as its design highlights.
Data Types
Set of values together with set of operations called data type.C++ data types classified into three
categories:
1.Simple data type
2.Structured data type
3.Pointers
Integral Data Types
I. char
II. short
III. int
IV. long
V. bool
VI. unsigned char
VII. unsigned short
VIII. unsigned int
IX. unsigned long
Floating-Point Data Types :
I. float
II. double
III. long double
Floating-Point Data Types :
I. float
II. double
III. long double
Standard Library
The C++ Standard Library can be categorized into two parts:
1-The Standard Function Library: This library consists of general-purpose,stand-alone functions that are not part of any class. The
function library is inherited from C.
2-The Object Oriented Class Library: This is a collection of classes and associated functions.
Variable Types
I. Arithmetic Operators
II. Relational Operators
III. Logical Operators
IV. Bitwise Operators
V. Assignment Operators
VI. Misc Operators
1.Arithmetic Operators.
3.Logical Operators
4.Bit-wise Operators
7.Misc Operators
Standard I/O Devices
Use iostream to extract (receive) data from keyboard and send output to the screen
IOstream contains definitions of two types:
1. istream – input stream
2. ostream – output stream
Basic IOstream variables:
1. cin – common input
2. cout – common output
cin and cout
To use cin and cout, the preprocessor directive #include <iostream> must be used
The declaration is similar to the following C++ statements:
1. istream cin;
2. ostream cout;
Input stream variables: type istream
Output stream variables: type ostream
FUNCTIONS
What are Functions?
A function is a group of statements that together perform a task. Every C program has at least onefunction, which is main(), and all
the most trivial programs can define additional functions. You can divide up your code into separate functions.
Predefined and User-Defined Functions
1) Predefined standard library functions – These are available to anyone who writes a C++ program. This saves the
programmer’s time from writing own functions. They are completely debugged, efficient and always produce a precise output. The
important contribution of the system-supplied functions is that they provide clarity to the program because they do not have to be
redefined. It reduces the source code, which saves time of the programmer.
2) User Defined functions – C++ language allows additional functions besides the built-in functions called the user-defined function.
It allows programmers to define their own functions. The programmer must code the logic of this type. In order to do so, a declaration
is needed.
Enumeration Data Type
An enumeration is a distinct type whose value is restricted to a range of values (see below for details), which may include several
explicitly named constants (“enumerators“). The values of the constants are values of an integral type known as the underlying type of
the enumeration.
Data types:
C++ simple data types:
1. integral (char, short, int, long, and bool)
2. enum
3. floating (float, double, long double)
C++ structured data types:
1. array
2. struct
3. union
4. class
>>> Arrays
C++ provides a data structure, the array, which stores a fixed-size sequential collection of elements of the same type. An array is
used to store a collection of data, but it is often more useful to think of an array as a collection of variables of the same type.
C++ Arrays in Detail
>>>Structures
Structure is a collection of variables of different data types under a single name. It is similar to a class in that, both holds a collection
of data of different data types.
How to define a structure variable?
Once you declare a structure person as above. You can define a structure variable as:
How to define a structure variable?
Once you declare a structure person as above.
Person Jack;
Here, a structure variable Jack is defined which is of type structure person.
When structure variable is defined, only then the required memory is allocated by the compiler.
How to access members of a structure?
The members of structure variable is accessed using a dot (.) operator.
Suppose, you want to access salary of structure variable Jack and assign it 98000 to it.
Jack.age=98000;
Strings
S.N. Function & Purpose
1 strcpy(s1, s2);Copies string s2 into string s1.
2 strcat(s1, s2);Concatenates string s2 onto the end of string s1.
3 strlen(s1);Returns the length of string s1.
4 strcmp(s1, s2);Returns 0 if s1 and s2 are the same; less than 0 if s1<s2; greater than 0 if s1>s2.
5 strchr(s1, ch);Returns a pointer to the first occurrence of character ch in string s1.
6 strstr(s1, s2);Returns a pointer to the first occurrence of string s2 in string s1.
The String Class in C++
The standard C++ library provides a string class type that supports all the operations mentioned above, additionally much more
functionality. We will study this class in C++ Standard Library
Pointers
What Are Pointers?
A pointer is a variable whose value is the address of another variable. Like any variable or constant, you must declare a pointer
before you can work with it.
Using Pointers in C++:
There are few important operations, which we will do with the pointers very frequently. (x) we define a pointer variables (y) assign the
address of a variable to a pointer and (z) finally access the value at the address available in the pointer variable. This is done by using
unary operator * that returns the value of the variable located at the address specified by its operand.
C++ Pointers in Detail
I/O Library Header Files
Inheritance
Derive quality and characteristics from parents or ancestors. Like you inherit features of your parents.
Types of Inheritance:
1. Single Inheritance.
2. Multilevel Inheritance.
3. Multiple Inheritance.
4. Hierarchical Inheritance.
5. Hybrid Inheritance.
Polymorphism
Polymorphism is one of the crucial feature of c++ it simply means one name and multiple forms.The function overloading and
operator overloading is known as compile time Polymorphism / static Polymorphism.
Data Abstraction
Data abstraction refers to, providing only essential information to the outside world and hiding their background details, i.e., to
represent the needed information in program without presenting the details.Data abstraction is a programming (and design)
technique that relies on the separation of interface and implementation.
Data Encapsulation
Data encapsulation is a mechanism of bundling the data, and the functions that use them and data abstraction is a mechanism of
exposing only the interfaces and hiding the implementation details from the user.C++ supports the properties of encapsulation and
data hiding through the creation of user-defined types, called classes. We already have studied that a class can contain private,
protected and public members
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