2. OOP: Object oriented programming language is the language which deals with the objects and classes.
a. Properties or features of OOP:
i. Encapsulation: Encapsulation is wrapping of data into a single unit. In this the data is bound together inside a class which is hidden from outside world.
Eg: class X
{
Int i=5;
Int j;
}
ii. Inheritance: It is the process of creating a new class from the existing one. This new class is the child class which inherits all the characteristics of the parent class.
Eg: class X
{
public int a;
Public int b;
}
Class Y:X
{
Public int a;
Public int b;
}
Static void main()
{
Y o=new Y();
o.a=6;
}
iii. Polymorphism: This is a process in which methods with same name performs different tasks.
This can be implemented in three ways:
a) Overloading : In this different methods with same method name performs different tasks based on different type of parameters.
Eg: class X
{
Public int add(int a, int b)
{
Return a+b;
}
Public int add(int a, int b, int c)
{
Return a*b*c;
}
}
Static void main()
{
X o=new X();
Int i=o.add(2,3);------------o/p=5
Int j=o.add(4,5,6);----------o/p=120
}
b) Overriding: In this different methods with same signature performs differently in parent class and child class. Here the parent function in the child class is completely replaced by other function. When a class is overridden then we can declare an object of child class as parent type.
Eg: class X
{
Virtual Public void print()
{
Console.writeline("parent");
}
}
Class Y:X
{
Override public void print()
{
Console.writeline("child");
}
}
Static void main()
{
X o=new X();
o.print();---------------o/p=parent
Y x=new Y();
x.print();---------------o/p=child
X z=new Y();
z.print();----------------o/p=child
}
c) Method hiding(shadowing): Is a process where the parent function is hidden in the child class using the keyword "new".
Eg:
class X
{
Public void print()
{
Console.writeline("parent");
}
}
Class Y:X
{
New public void print()
{
Console.writeline("child");
}
}
Static void main()
{
X o=new X();
o.print();---------------o/p=parent
Y x=new Y();
x.print();---------------o/p=child
X z=new Y();
z.print();----------------o/p=parent
}
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| Author: http://venkattechnicalblog.blogspot.com/ 26 Apr 2008 | Member Level: Diamond Points : 0 |
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Regards,
Venkatesan Prabu . J
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