Enumerated Property
using System;
namespace oopsProject
{
public enum cities {
public class Customer
{
int _custid;
string
_cname, _state;
double
_balance;
bool
_status;
cities
_city;
public
Customer(int _custid)
{
this._custid
= _custid;
//Get all other values from DB basing on given ID:
_cname = "prabhu";
_balance = 5000;
_status = false ;
_city = 0;
_state = "karnataka";
Country = "
}
//Read only Property
public int Custid
{
get { return _custid; }
}
//Read write Property
public string Cname
{
get { return _cname; }
set {
_cname = value; }
}
//Read write Property
public bool Status
{
get { return _status; }
set {
_status= value; }
}
//Read write Property with a condition
public double Balance
{
get
{
if
(_status)
return _balance;
else return 0;
}
set
{
if (value >= 500)
_balance = value;
}
}
// enumerated property
public cities city
{
get{return _city;}
set{_city = value;}
}
// setting scope of property Accessor independently (2.0)
public string state
{
get { return _state;}
protected
set { _state = value;}
}
//Automatic Properties 3.0
public
string Country
{
get;
private
set;
}
}
}
|
Enumerated Property
These are property which is defined with a list of
constants to choose from. to define these type of properties first we need to
declare all the constants under a type known as “enum” .An enum is a collection
of constants, which should be declared as following.
Syntax –
[<modifiers>] enum
<name> {<list of values >};
|
public enum Days {Monday, Tuesday, Wednesday, Thursday,
Friday};
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If this enum is used as a type for any property we call it as
enumerated property.
- Declaring a variable of
enum type.
Days weekday = 0;
or
Days weekday = Days.Wednesday ;
|
- Now for the variable
weekday we can define a property as Following:
public Days weekday
{
get {return weekday;}
set { weekday = value;}
}
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New Features to
Properties:-
<!--[if
!supportLists]-->
<!--[endif]-->In C# 2.0, there are given an option to
define a property setting the scope of each property Accessor independently.
Eg: State property we have defined under customer class.
<!--[if
!supportLists]-->
<!--[endif]-->In C# 3.0, we were given with an option
automatic properties, which allows us to define a property without any variable
declaration for the property, So set and get blocks doesn’t contain any code in
them, but it is must to define both get and set blocks.
Eg: Country Property in above customer class.
Consuming the
Properties:-
- Add a class
TestCustomer.cs and write the following:
using System;
namespace oopsProject
{
class TestCustomer
{
static void
{
Customer obj = new Customer(101);
Console.WriteLine(obj.Custid);
//Assignment i not possible as property is read only
//obj.Custid = 102;
Console.WriteLine(obj.Cname);
obj.Cname = "xyz";
Console.WriteLine(obj.Cname);
Console.WriteLine(obj.Status
);
//Balance will be zero here as status is inactive
Console.WriteLine(obj.Balance);
obj.Status = true;
Console.WriteLine(obj.Status);
// now it returns balance as status is active
Console.WriteLine(obj.Balance);
obj.Balance = 400; //assignment fails
// here as it is less than 500
obj.Balance = 400;
Console.WriteLine(obj.Balance);
// assignment succeeds as it is greater than 500
obj.Balance = 600;
Console.WriteLine(obj.Balance);
Console.WriteLine(obj.city);
obj.city = cities.Hyderabad;
Console.WriteLine(obj.city);
Console.WriteLine(obj.state);
// Assigning value to the property is invalid as current
//class is not a child class of customer
//obj.state = "AP";
Console.WriteLine(obj.Country);
Console.ReadLine();
}
}
}
|
Note – Just like we have Abstract method and
Virtual method, we can define Property also as abstract and virtual. So that we
can override them under Child class.
Porperty
- Destructor are actually responsible for
deallocation of memory used by objects but in managed languages deallocation is
taken care by garbage collector for which destructor are not required, whereas
in some situation we may be using any unmanaged resource like files, database
etc. which will not be under control of garbage collector, in such scenario we
use these destructors for managing those unmanaged resources.
Properties
If at all a class contains any values in it that should be
accessible outside of the class. Access to those values can be provided in two
different ways –
- By storing the value in public variable access to the value can be given where anyone can get the value or set with a new value.
|
public class Show
{
public int x = 100;
}
……………………….
Show obj = new Show ();
int a = obj x
;
// Getting the value
int.x =
200;
// Setting the value
|
- By storing the value in a private variable also access to the value can be given by defining a property on that variable, where we can provide the access to the value in three different ways.
a.
Both get and set access (read | write
property)
b.
only get access (Read only property)
c. only
set access (Write only property)
Syntax:-
|
[<modifiers>]<type> <name>
{
[get {- stmts}] // get Accessor
[set {- stmts}] // Set Accessor
}
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- The code which is present in the Get block
is executed whenever we try to capture the value of property.
|
string str = “Hello”;
int len = str.Length;
|
- The code under set box gets executed whenever
we are trying to assign in new value to the property.
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Console.BackgroungColor = ConsoleColor.Blue;
|
-
If the property is defined with both get and
set blocks it is a read | write property.
-
If defined only with get block, it is a read
only property.
-
If defined only with a set block it is a write
only property.
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