1. Dr. Bhargavi Dept of CS CHRIST 9426669020
Beginning with C++
Dr. Bhargavi
Dept of CS
CHRIST

2. Header files Comments // or /* comments */
Output Operator, bitwise shift left operator cout<<“print it”<<string;
Assert.h = macros and debugging
Ctype.h = test properties of function prototype
Float.h = float size limit
Limits.h = integral size limits
Math.h = math library function
Stdio.h = standard input output
Stdlib.h = convert number to text, etc
String.h = c-style string processing
Time.h = time land date manipulation
Iostream.h = standard input output functions
Iomanip.h = formatting streams of data
Fstream.h = input to file and output from file functions

3. New header files
Utility = has classes and functions used by other header files
Vector, list, deque, queue, set, map, stack, bitset = standard containers
Functionals = algorithms of standard library
Memory = allocate memory
Iterator = manipulates data
Algorithms = manipulate data in standard library containers
Exception, stdexcept = exception handling
String = class string definition
Sstream = input from string to memory and output to string in memory
Locale = stream processing for different language
Limits = define numerical data type limits
Typeinfo = run time type identification

4. Namespace Defines scope of identifiers used in a program.
Std is namespace according to ANSI C++ standards
It brings all the identifiers defined in “std” to current global scope.
‘using’ and ‘namespace’ are keywords of C++.

5. Return type of Main() Is Integer
Therefore, every program has to end with return 0.
Default return type of all the functions in C++ is ‘int’.
Consequence?
Warning or error.
Eg. Average of Two numbers
Average of Ten numbers

6. Variables Can be declared anywhere in the program.
Must be declared before used.

7. Output operator cascading
Cout<<“Print variable:”;
Cout<<string;
Cascading can be done:
Cout<<“Print Variable:”<<num1<<endl;
C-out
Called standard output stream
Represents screen
We can redirect output to other devices or memory in the form of file.
<< is called insertion operator
<< is bitwise left shift operator
Operator overloading can be done on it for additional functionality
Works such as printf();

8. Input operator cascading
Cin>>number1;
C-in
Operator >> is known as extraction or get from operator.
Similar to scanf() operation
>> operator can be overloaded.
Eg. cin>>num1;
cin>>num2;

9. Cascading i/0 operators
Input and output operators can be cascaded.
Eg:
Cout<<“Sum=”<<sum<<“\n”;
Cout<<“Sum”<<sum<<“\n”<< “ ,Average=”<<average<<“\n”;
Output: Sum=14, Average=17;

10. Class Major features of C++ is a class.
Binding together data and functions
Is a user defined datatype
Eg.
1. use of class
2. class box

11. Structure of c++ Program
INCLUDE FILES
CLASS DECLARATION
MEMBER FUNCTIONS DEFINITION
MAIN FUNCTION PROGRAM

12. END OF CHAPTER 2
THANK YOU

13. Tokens, expressions & control structures
Dr. Bhargavi
Dept of CS
CHRIST

14. tokens Definition? The smallest individual units in the program.
How many tokens are there in C++? 5.
Which are they?
Keywords, Identifiers, Constant, Strings Operators.

15. keywords

16. Identifiers and constants
Identifier definition?
It refers to the names of variables, functions, arrays, classes, etc.
Rules?
Only alphabetic characters, digits and underscores
Cannot start with digit
Considers upper and lower case Distict
Keywords cannot be identifiers
Constants definition?
Fixed values that do not change during execution.
Literal constants do not have memory locations.
What is wchar_t?
Wide character literal introduced by ANSI C++.
Intended for character sets that do not fit a character into single byte.
It begins with letter L.

17. Basic data types

18. Size and range of data types

19. Storage classes AUTOMATIC EXTERNAL STATIC REGISTER LIFETIME
Function block
Entire program
Entire Program
Function Block
VISIBILITY
Local
Global
INITIAL VALUE
Garbage
STORAGE
Stack segment
Data segment
CPU segment
PURPOSE
Local variables used by single function
Global variables used throughout the program
Local variables retaining values throughout the program
Variables using CPU registers for storage purpose
KEYWORDS
auto
extern
static
register

20. Dynamic initialization of variables
C++ allows initialization of variables at run time.
Eg. int n = strlen(string);
Eg. float area = 3.14 * rad * rad;
Eg. float average = sum/I;

21. Reference variables What is this?
It’s the alias (alternative name) for previously defined variable.
One memory location, two or more names.
Condition?
Must be initialized at the time of declaration.
Represented by?
& but, it is not an address operator.
Use?
Manipulation of objects by reference. Avoids copying and pasting of object variables to and fro.
Eg. total may have an alias as sum and can refer to same variable.
Syntax: data-type & reference-name = variable-name
Eg. float total = 100;
float & sum = total;
Eg. 3_ReferenceVariable.cpp

22. Operators in c++

23. Scope resolution operator
C++ is also block structured language.
Use?
Variables with same name can have different meaning in different blocks.
Even memory location is different even though the name is same in the same program.
Limitation of C: global variable cannot be accessed and manipulated within the local blocks.
Resolved by C++?
Yes.
How?
Using scope resolution operator.
Eg. Check 3_ScopeResolOpr.cpp
Detect output of 3_ScopeResolOprEx2.cpp
Also check 3_1ScopeResolutionOperator.cpp

24. Member dereferencing operator
Can we access class members using pointers?
Yes.
How?
Using 3 pointer to member operators.
Detailed discussion will be done during the chapter of pointers.

25. Memory management operator
C has the concept of malloc(), calloc() and free().
Although C++ supports these function, in addition, also support unary operators for doing that task in easy and better way.
How?
Using new and delete.
Also called free store operators.
The life time of the operators are in direct control of the programmers.
Syntax: pointer-variable = new data-type(value);
Syntax: delete pointer-variable;
For array:
Syntax: pointer-variable = new data-type[size];
Syntax: delete [size]pointer-variable;
Eg. 3_new-delete.cpp
Eg. 3_3UseOfBad_AllocException.cpp

26. manipulators
In detail we will study in chapter of streams and i/o manipulators.
Just check the output of the program as of now.
Eg. 3_manipulators.cpp

27. Self study 1. explicit type casting 2. control structures of If Switch
Do-while
While
For

28. END OF CHAPTER 3
THANK YOU

29. Dr. Bhargavi Dept of CS CHRIST 9426669020
Functions in C++
Dr. Bhargavi
Dept of CS
CHRIST

30. Function prototype
It provides three information to compilers called template.
Which 3 information?
Name of function, number and type of arguments and type of return values.
Any violation in match of these three information results to compilation error.
Form: type function-name (argument-list);
Eg. float vol(int x, float y, float z) {
//function body }
Call statements: float cube = vol(b1,w1,h1);
Eg: 4_FunctionPrototype.cpp

31. Function arguments
Call by value: passing arguments to a function copies the actual value of an argument into the formal parameter of the function. Eg. 4_CallByValue.cpp
Call by pointer: passing arguments to a function copies the address of an argument into the formal parameter. Eg. 4_CallByPointer.cpp
Call by reference: passing arguments to a function copies the reference of an argument into the formal parameter. Eg. 4_CallByReference.cpp
Return by reference: When a function returns a reference, it returns an implicit pointer to its return value. Eg. 4_ReturnByReference.cpp

32. Inline function What is the objective of using function?
To save memory space.
But, memory space is saved at the cost execution time due to execution of long function body, pushing arguments to stack, jumping to and fro function, returning to calling function.
Effect is minimum when applications are small, but affects execution time worst when application grows.
Problem?
Yes. Solution?
1. Macro.
But, drawback is being not functions, compile time errors are not checked.
2. Inline Function.

33. Inline function
Definition: The function that is expanded in line when it is invoked.
How it works?
Compiler replaces function call with corresponding function code.
What is the effect?
Makes program run faster. Execution time reduces.
Similar to macros expansion?
Yes. Then what is the advantage.
Error checking at compile time is done.
If its so good, y can’t we make all functions inline?
If functions are large, inline effect diminish.

34. Inline expansion may not work in situations:
Functions returning values
Functions with loops, switch or goto stmts.
Functions containing static variables
Functions that are recursive
Eg. 4_1InlineFunctions.cpp

35. Default arguments
Can you call a function with arguments without providing the arguments?
Yes or No?
C++ provides this facility by Default Arguments. We can call a function without specifying all its arguments.
How?
Provide default values to arguments.
Advantage?
No need to specify arguments at each function call.
Add new parameters to function without making call statements complex.
Also allows to override the default value.
Used to combine similar funtions.
Remember.
Only trailing arguments can have default values.
Eg. 4_2DefultArgument.cpp

36. Const arguments Can arguments be constant? Yes. How.
Eg. int strlen(const char *p);
Eg. length(const string &s);
Compiler is told by keyword ‘const’ that function should not modify the argument.
Eg. 4_constant.cpp

37. Function overloading Define overloading.
Use of same thing for different purposes.
Another name?
Function Polymorphism.
We can design a family of function with same name but different argument list.
Calculating area depending on shape.
Eg. 4_5FunctionOverloading.cpp

38. END OF CHAPTER 4
THANK YOU