List Manipulation in C# using Linq

Question

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

namespace ConsoleApplication1
{

    public cla         


        

Answer 1

Everything leppie said - plus:

int index = mylist.FindIndex(p => p.id == 1);
if(index<0) {
    mylist.Add(car3);
} else {
    mylist[index] = car3;
}

This just uses the existing FindIndex to locate a car with id 1, then replace or add it. No LINQ; no SQL - just a lambda and List<T>.

Answer 2

If you wanted to do an update to multiple elements...

foreach (var f in mylist.FindAll(x => x.id == 1))  
{    
    f.id = car3.id;  
    f.color = car3.color;  
    f.make = car3.make;  
}  

Answer 3

//Item class
Class Item
{
   public string Name { get; set; }
}

List < Item > myList = new List< Item >()

//Add item to list
Item item = new Item();
item.Name = "Name";

myList.Add(Item);

//Find the item with the name prop

Item item2 = myList.Find(x => x.Name == "Name");

if(item2 != null)
   item.Name = "Changed";

Answer 4

Just one question, why do I have to write a Update function for something that seems so basic for a list? There should be standard methods for Lists like Add(), Delete(), Edit(), Insert(), Replace() ....Find()

Answer 5

List<AvailabilityIssue> ai = new List<AvailabilityIssue>();

ai.AddRange(
    (from a in db.CrewLicences
        where
            a.ValidationDate <= ((UniversalTime)todayDate.AddDays(30)).Time &&
            a.ValidationDate >= ((UniversalTime)todayDate.AddDays(15)).Time
        select new AvailabilityIssue()
        {
            crewMemberId = a.CrewMemberId,
            expirationDays = 30,
            Name = a.LicenceType.Name,
            expirationDate = new UniversalTime(a.ValidationDate).ToString("yyyy-MM-dd"),
            documentType = Controllers.rpmdataController.DocumentType.Licence
        }).ToList());

Answer 6

This is not LINQ2SQL.

Also, LINQ is not used for updating, only to query for objects.