LINQ offer query against object . You can query an object from in memory collection.Array, list, collections can be complex , and can hold data of a particular type of object. You can query on collection objects with LINQ.
Before the introduction of LINQ , developer used for loop to retrieve data from collections and write condition to filter the data. That was very hectic . LINQ introduced simple technique to retrieve the data buy simple writing declarative code that reduce effort and clean, structure code with more accuracy and faster than for loop.
Below is the example of LINQ to Object .The first example is of a simple query on a array.The second example is of a collection of a particular type of object.
Example
Before the introduction of LINQ , developer used for loop to retrieve data from collections and write condition to filter the data. That was very hectic . LINQ introduced simple technique to retrieve the data buy simple writing declarative code that reduce effort and clean, structure code with more accuracy and faster than for loop.
Below is the example of LINQ to Object .The first example is of a simple query on a array.The second example is of a collection of a particular type of object.
Example
using
System;
using
System.Collections.Generic;
using
System.Data.SqlClient;
using
System.Data.Sql;
using
System.Data;
using
System.Linq;
using
System.Collections;
namespace
ConsoleApplication1
{
class
Program
{
static
void
Main(string[]
args)
{
string[]
country = { "India",
"Brazil",
"China",
"USA",
"Pakistan",
"South
Afrika",
"Japan",
"Russia",
"Poland",
"Sweden"
};
/*
Example 1 (Simple Select Statement) */
var
AllCountry = from
c in
country select
c;
Console.WriteLine("List
of Country");
Console.WriteLine("----------------");
foreach
(var
c in
AllCountry)
{
Console.WriteLine(c);
}
Console.ReadLine();
/*
Example 3 (LINQ on Array List) */
ArrayList
myList = new
ArrayList();
myList.Add(
new
student
{
name
= "John",
roll
= 12,
age
= 9
});
myList.Add(
new
student
{
name
= "John1",
roll
= 14,
age
= 8
});
myList.Add(
new
student
{
name
= "John2",
roll
= 13,
age
= 7
});
myList.Add(
new
student
{
name
= "John3",
roll
= 15,
age
= 8
});
var
query = from
student
s in
myList
where
s.age > 7
select
s;
Console.WriteLine("List
of Student Over 7 Years of Age");
Console.WriteLine("--------------------------------------");
foreach
(student
c in
query)
{
Console.WriteLine("Name
: "
+ c.name);
Console.WriteLine("Roll
: "
+ c.roll);
Console.WriteLine("Age
: "
+ c.age);
Console.WriteLine("\n");
}
Console.ReadLine();
}
}
}
public
class
student
{
public
string
name { get;
set;
}
public
int
roll { get;
set;
}
public
int
age { get;
set;
}
}
Output :
List of Country
----------------
India
Brazil
China
USA
Pakistan
South Afrika
Japan
Russia
Poland
Sweden
List of Student Over 7 Years of Age
--------------------------------------
Name : John
Roll : 12
Age : 9
Name : John1
Roll : 14
Age : 8
Name : John3
Roll : 15
Age : 8
----------------
India
Brazil
China
USA
Pakistan
South Afrika
Japan
Russia
Poland
Sweden
List of Student Over 7 Years of Age
--------------------------------------
Name : John
Roll : 12
Age : 9
Name : John1
Roll : 14
Age : 8
Name : John3
Roll : 15
Age : 8
