Generic feature of. Net Framework.
It was added in the version of 2.0. Generic allow us delay declaration of the data type . User defined class , structure can be written and can be used as generic type during passing and initialization.
During compilation, compiler know how to handle the newly generated type. Generic is type safe and optimize code reuse.
Some points about generic
Here is the example of how a generic type is declared.
Initialize Constructor :
Generic type can be use to initialize a constructor. We can pass that Generic type to the constructor of a class, depending upon the declaration. Here is a example.
Generic Method : A Method can also be Generic, we can pass generic type as a value type or reference type depending upon the declaration, the parameter can be single or multiple parameter. Generic support both.
Generic delegate : in the previous chapter we have seen, delegates are of three type
Generic interface : an interface can be declared using Generic type. Here is the example of interface using Generic type.
It was added in the version of 2.0. Generic allow us delay declaration of the data type . User defined class , structure can be written and can be used as generic type during passing and initialization.
During compilation, compiler know how to handle the newly generated type. Generic is type safe and optimize code reuse.
Some points about generic
- You can create class, structure, interface, method, delegates define by the user, considered a kind of type.
- Generic comes under the namespace System.Collections.Generic
- Generic are type safe, no need to convert from object to actual type.
- Generic use the syntax , <T> is generic type.
- Genetic reduce overhead of explicit and implicit conversion, because during initialization , you are telling what type of data , will be hold in the collection.
Here is the example of how a generic type is declared.
using
System;
using
System.Threading;
using
System.Collections.Generic;
class
Student<T1,
T2>
{
//Generic
Type Variable Declaration
private
T1
mAge;
//Generic
Type Method
public
void
GetFees(T1
value)
{
//State
ment
}
//
Return Generic Type
public
T2
genericMethod(T2
mAddress)
{
T2
obj;
obj=mAddress;
return
obj;
}
//Generic
Type Property
public
T1
StudentProperty
{
get
{
return
mAge;
}
set
{
mAge
= value;
}
}
}
Initialize Constructor :
Generic type can be use to initialize a constructor. We can pass that Generic type to the constructor of a class, depending upon the declaration. Here is a example.
using
System;
using
System.Threading;
using
System.Collections.Generic;
class
Student<T1,
T2>
{
T1
Obj1;
T2
Obj2;
//Constructor
Initialisation
public
Student(T1
a, T2
b)
{
Obj1
= a;
Obj2
= b;
}
public
void
ShowData()
{
Console.WriteLine("Obj1
:"
+ Obj1.ToString());
Console.WriteLine("Obj2
:"
+ Obj2.ToString());
}
}
class
School
{
static
void
Main(string[]
args)
{
//Example
1
Student<string,
string>
myObj1;
myObj1
= new
Student<string,
string>(
"Hellow",
"
World");
myObj1.ShowData();
//Example
2
Student<int,
int>
myObj2;
myObj2
= new
Student<int,
int>(111,22);
myObj2.ShowData();
Console.ReadKey();
}
}
Generic Method : A Method can also be Generic, we can pass generic type as a value type or reference type depending upon the declaration, the parameter can be single or multiple parameter. Generic support both.
using
System;
using
System.Threading;
using
System.Collections.Generic;
class
Student<T1,
T2>
{
T1
Obj1;
T2
Obj2;
//Generic
Type Methos
public
void
MethodReturnGeneric<T1>(T1
a, T2
b)
{
T1
retu;
retu
= a;
}
//Generic
Type Parameter , Pass By value
public
void
Parameter_PassBy_Value(T1
a,T2
b)
{
Obj1
= a;
Obj2
= b;
Console.WriteLine("Obj1
:"
+ Obj1.ToString());
Console.WriteLine("Obj2
:"
+ Obj2.ToString());
}
//Generic
Type Parameter , Pass By Reference
public
void
Parameter_PassBy_Reference(ref
T1
a, ref
T2
b)
{
Obj1
= a;
Obj2
= b;
Console.WriteLine("Obj1
:"
+ Obj1.ToString());
Console.WriteLine("Obj2
:"
+ Obj2.ToString());
}
}
class
School
{
static
void
Main(string[]
args)
{
//Example
1
Student<string,
string>
myObj1=new
Student<string,
string>();
myObj1.Parameter_PassBy_Value("Hello",
"World");
//Example 2
string
str1 = "C#";
string
str2 = "Programming";
myObj1.Parameter_PassBy_Reference(ref
str1, ref
str2);
Console.ReadKey();
}
}
Generic delegate : in the previous chapter we have seen, delegates are of three type
- Single cast
- Multicast
- Generic.
class
School
{
public
delegate
T1
StudentCall(T1
a, T2 b);
static
void
Main(string[]
args)
{
StudentCall<int,
int>
gdInt = new
StudentCall<int,
int>(Example1);
}
public
static
int
Example1(int
a,
int
b)
{
return
(a
+ b);
}
public
static
string
Example2(string
a,
string
b)
{
return
(a
+ b);
}
public
static
int
Example3(int
a,
int
b)
{
return
(a
* b);
}
public
static
string
Example3(string
a,
string
b)
{
return
(a
+ b);
}
public
static
string
Example4(string
a,
int
b)
{
return
(b.ToString());
}
}
Call The
deligate:
School.StudentCall<int,
int>
obj = School.Example1;
Response.Write(School.Example1(5,
6));
//Output:11
Console.WriteLine(School.Example2("Hellow
",
"World").ToString());
//Output:Hellow
World
Generic interface : an interface can be declared using Generic type. Here is the example of interface using Generic type.
using
System;
using
System.Threading;
using
System.Collections.Generic;
public
interface
IStudent1<T>
: ICollection<T>
{
}
public
interface
IStudent2<T>
: IEnumerable<T>
{
}
public
interface
IStudent3<T>
: IList<T>
{
}
public
interface
IStudent4<T>
: ICollection<T>
{
}
Example 1
Example 2
Example 1
public
interface
Student<T>
: IEnumerable<T>
{
int
Count { get;
}
bool
Contains(T
a);
void
CopyTo(T[]
array, int
ArrayIndex);
bool
IsReadOnly { get;
}
void
Add(T
a);
void
Clear();
bool
Remove(T
a);
}
Example 2
public
interface
Student<T>
: IList<T>
{
int
Count { get;
}
bool
Contains(T
a);
void
CopyTo(T[]
array, int
ArrayIndex);
bool
IsReadOnly { get;
}
void
Add(T
a);
void
Clear();
bool
Remove(T
a);
}
Example 3
public
interface
Student<T>
: ICollection<T>
{
int
Count { get;
}
bool
Contains(T
a);
void
CopyTo(T[]
array, int
ArrayIndex);
bool
IsReadOnly { get;
}
void
Add(T
a);
void
Clear();
bool
Remove(T
a);
}
