Tutorial on Basic Concepts of C++ Program Part 1

Structure of C++ Program:

• C++ Program contain Four Sections. 
• These Sections may be placed in Separate code Files.
• Most popular Compiler systems are UNIX AT & T C++ , Turbo C++ , Microsoft Visual C++.

Include Files

Class Declaration

Member Function Definition

Main Function Program

Output operator:

1. This statement  Cout << " c++ is better than c. " ; introduces two new C++ Features i.e Cout and << . 
2. The operator << is called the Insertion or Put to Operator. 
3. The identifier Cout is a predefined object that represents the standard output stream in c++. 
4. << Operator is also known as bitwise left-shift operator.

Note: Both Cout << and printf() are used for displaying an Output.

Input operator:

1. The statement  Cin >> number;  is an input statement. 
2. The identifier Cin is a predefined object in C++ that represents the standard input stream. 
3. The operator >> is known as Extraction or get from operator. It extracts the value from the keyboard and assign it to the variable on the right of the identifier Cin.

Note: 

• Both scanf() and Cin is used for input values.
• Both << and >> can also be overloaded.

Return Type of main() :

1. In C++ main() returns an integer type value to the operating system. Thus every main() in C++ should end with a return(0) statement, otherwise a warning or an error Might occur. 
2. The default return type for all functions in C++ is int.

Example:

     main()

     {

     ...........

     ...........

    return(0);

     }

Manipulators:

1. Manipulators are the Operators that are used to Format the data display. 
2. The most commonly used manipulators are endl and setw.
3. " endl " manipulator when used in an output statement, it causes a linefeed to be inserted. It has same effect as that of newline character " \n ".

Cascading of I/O Opertors:

• Cout<< "Sum=" << sum<<"\n";

The above Statement first sends the string "Sum=" to Cout and then sends the value of sum.

• Cin>> a >> b;

The values are assigned from Left to Right. If we press two values i.e 10 and 5 from the keyboard then 10 will be assigned to "a" and "5" to b.

• This is one statement and provides one lines of output.

                           Cout<< "Sum=" << sum<<" , "

                                  << "Average="<< average<< "\n";

Output:

 Sum=30 , Average=7

• This is one statement but provides two lines of output.

                               Cout<< "Sum=" << sum<<" \n "

                                      << "Average="<< average<< "\n";

Output:

 Sum=30 

 Average=7

Posted by Roky

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