Page 80 - DCAP404 _Object Oriented Programming

Unit 4: Classes and Objects

void salary( ); Notes
void get_info( );
void display_info( );
};
employee x, y; //creates x and y - two objects of the class employee
By now it should be clear to you that you can use a class just as you use a data type. In fact you can
also create an array of objects of a particular class.

Did u know? What is the difference between defining a class member function completely
within its class or to include only the prototype and later its definition?

The only difference between defining a class member function completely within its class
or to include only the prototype and later its definition, is that in the first case the function
will automatically be considered an inline member function by the compiler, while in the
second it will be a normal (not-inline) class member function, which in fact supposes no
difference in behavior.

Self Assessment

Fill in the blanks:
1. A class is an expanded concept of a data structure: instead of holding only data, it can hold
both data and…………………. .

2. By default, all members of a class declared with the ………………….. keyword have private
access for all its members.
3. All is very similar to the declaration on data structures, except that we can now include
also functions and members, but also this new thing called …………………... .
4. A class provides a template, which defines the member functions and ………………… that
are required for objects of a class type.
5. A class must be defined prior to the class …………………... .

4.2 Defining Member Functions

We have learnt to declare member functions. Let us see how member functions of a class can be
defined within a class or outside a class.
A member function is defined outside the class using the :: (double colon symbol) scope resolution
operator. The general syntax of the member function of a class outside its scope is:
<return_type> < class_name>:: <member_function>(arg1, arg2....argN)
The type of member function arguments must exactly match with the types declared in the class
definition of the <class_name>. The Scope resolution operator (::) is used along with the class
name in the header of the function definition. It identifies the function as a member of a particular
class. Without this scope operator the function definition would create an ordinary function,
subject to the usual function rules of access and scope.

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