How to use Select projection in LINQ?

Question

Ravi Vishwakarma · Answer

In LINQ Select projection operator is used for selecting data from collection or SQL Database. The select operator is the same as the SQL select clause operator.
Syntax in C# 
var result = from object-of-collection in collection 
and  and  and  and  select object-of-collection ;
var result = from s in student
and  and  and  and  select new {new-variable-name = object-of-collection.member, ….. };
var result = collection.Select( argument => argument );
Example. 
using System;
using System.Collections.Generic;
using System.Linq;
public class Program
{
and public static void Main()
and {
and  Listandlt;Student> students = new Listandlt;Student>()
and  {
and  new Student() { StudentId = 1, Name = 'Asu', Marks = 500 },
and  new Student() { StudentId = 2, Name = 'Shyam', Marks = 300 },
and  new Student() { StudentId = 3, Name = 'Shriyam', Marks = 400 },
and  new Student() { StudentId = 4, Name = 'Sunny', Marks = 550 },
and  new Student() { StudentId = 5, Name = 'Ram', Marks = 600 },
and  new Student() { StudentId = 6, Name = 'Krishna', Marks = 700 },
and  new Student() { StudentId = 7, Name = 'Anupam', Marks = 550 }
and  };
and  // select projection using first sysntax
and  var result1= from student in students 
and  and  and and and and and and and and and   select student ;
and  Console.WriteLine('Using First Syntax :
');
and  result1.ToList().ForEach(item => Console.WriteLine('StudentName is {0}, ID is {1}, and Marks is {2}', item.Name, item.StudentId, item.Marks) );
and  var result2 = from student in students
and  and and and and and and and and and and and and   select new {Name =student.Name,ID = student.StudentId,Marks = student.Marks };
and  Console.WriteLine('
Using Second Syntax :
');
and  result2.ToList().ForEach(item => Console.WriteLine('StudentName is {0}, ID is {1}, and Marks is {2}', item.Name, item.ID, item.Marks) );
and  var result3 = students.Select( student => student);
and  Console.WriteLine('
Using Select method Syntax :
');
and  result3.ToList().ForEach(item => Console.WriteLine('StudentName is {0}, ID is {1}, and Marks is {2}', item.Name, item.StudentId, item.Marks) );
and  Console.ReadLine();
and }
}
class Student
{
public int StudentId { get; set; }
public string Name { get; set; }
public int Marks { get; set; }
}
Output 
Using First Syntax :
StudentName is Asu, ID is 1, and Marks is 500
StudentName is Shyam, ID is 2, and Marks is 300
StudentName is Shriyam, ID is 3, and Marks is 400
StudentName is Sunny, ID is 4, and Marks is 550
StudentName is Ram, ID is 5, and Marks is 600
StudentName is Krishna, ID is 6, and Marks is 700
StudentName is Anupam, ID is 7, and Marks is 550
Using Second Syntax :
StudentName is Asu, ID is 1, and Marks is 500
StudentName is Shyam, ID is 2, and Marks is 300
StudentName is Shriyam, ID is 3, and Marks is 400
StudentName is Sunny, ID is 4, and Marks is 550
StudentName is Ram, ID is 5, and Marks is 600
StudentName is Krishna, ID is 6, and Marks is 700
StudentName is Anupam, ID is 7, and Marks is 550
Using Select method Syntax :
StudentName is Asu, ID is 1, and Marks is 500
StudentName is Shyam, ID is 2, and Marks is 300
StudentName is Shriyam, ID is 3, and Marks is 400
StudentName is Sunny, ID is 4, and Marks is 550
StudentName is Ram, ID is 5, and Marks is 600
StudentName is Krishna, ID is 6, and Marks is 700
StudentName is Anupam, ID is 7, and Marks is 550

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How to use Select projection in LINQ?

Ethan Karla

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