Working with OOP synopsis concepts:-
Based on the style of programming the languages are divided into three types Procedure structure OOPL 1960’s A! GOL 1970’s
- No loops COBOL
- No arrays BASIC
- NO dynamic ‘C’
- Memory allocation
Problems in C –language:-
P1 Main ()
Int Sal = 4000;
Print f (“%d”, Sal);
The data type's limits are not controlled at run time.
P2 Main ()
Int I = 500 * 500/500;
Print f (“%d”, i);
No proper implicit procedure for calculation
Long Sal = 5000;
// global variable
Void F2 ()
Void Marketing Details ()
Long Sale = 500000; Sale = Sale + Sale ;
No Security for the ‘DATA’
- To overcome all these problems, ANSI (American National Standard Institute) defined a set of rules called “OOPS”
When a language supports, the following oops concepts then that language is called an object-oriented programming language (OOPL).
- Encapsulation (Data Hiding)
- Abstraction (Providing information)]
- Polymorphism (overloading)
- Encapsulation is a concept of data hiding.
- Abstraction is a concept of providing full information about an entity (data binding)
- Polymorphism is the concept of writing more than one function with the same and different arguments.
- Inheritance is a concept of deriving the features from base to derived class
- To work with OOPS concepts, classes, and objects are required.
- Classes are a logical representation
- An object is a physical representation
As per.net, A class is a collection of
- Fields: private data of classes is called a field.
- Properties: it defines the look and feel of an object
- Methods: when an object can do is called a method
- Events: what a user can do with an object is called an “event”
- The instance of classes is called as an object
Instance means copy
Syntax to write a class:
Class C1 Name
Private int x,y;
Private String s;
Public void print ();
Private and public are assessed specifiers
which provides the scope of risibility
Syntax to create an object:-
Logical Diagram on class and object:-
Test obj = new Test()
- Object can access only public data.
- Object can not access private data
on Classes and objects:-
Classes must be declared in GD only.
- Open windows form Application project
- Place a button
- Code in GD (Before button 1 click)
Private int x, y ;
// fields (or)
Public void Read (int a, int b)
//a and b are value types,
Public void print ()
Int K = x +y ;
Message Box >show (“The sum is ” + K);
//test Code for Button 1
Test t1 = new Test () T1.Read (10,20);
// output is ‘30’
Test t2 = new Test ();
// output is ‘0’
Test t3 = new Test ();
Test t3 = t1;
//output is ‘30’
Execute the project
- Fields of a class are also called Instance variables.
- In C#.net by default, every class will be inherited from System. object class
- System. object class contains four methods
- Get Hash code ()
- Get Type ()
- Equals ()
- To string ()
- In C# .net every class contains a minimum of 4 methods.