Query by position : Index « LINQ « C# / CSharp Tutorial






using System;
using System.Collections;
using System.Collections.Generic;
using System.Text;
using System.Linq;
using System.Reflection;

class Person {
    int _id;
    int _idRole;
    string _lastName;
    string _firstName;

    public int ID {
        get { return _id; }
        set { _id = value; }
    }

    public int IDRole {
        get { return _idRole; }
        set { _idRole = value; }
    }

    public string LastName {
        get { return _lastName; }
        set { _lastName = value; }
    }

    public string FirstName {
        get { return _firstName; }
        set { _firstName = value; }
    }
}
class Program {
    static void Main(string[] args) {
        List<Person> people = new List<Person> {
               new Person { ID = 1, IDRole = 1, LastName = "A", FirstName = "B"},
               new Person { ID = 2, IDRole = 2, LastName = "G", FirstName = "T"},
               new Person { ID = 3, IDRole = 2, LastName = "G", FirstName = "M"},
               new Person { ID = 4, IDRole = 3, LastName = "C", FirstName = "G"}
            };
        var query = people.Select((p, index) => new { Position = index, p.FirstName, p.LastName });
    }
}








22.49.Index
22.49.1.Query by position
22.49.2.Use an indexed Where clause (where the length of the number's name is shorter than its value)
22.49.3.Select - Indexed: prints the value of the integer and whether it matches its index in the array
22.49.4.Use index when querying array with LINQ