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Need help using Linq to transform a list into a different list

Lets say I have a list that contains 1 record:
[
{
"AccountNumber": 1234,
"eDocConfirms": true,
"eDocStatements": true,
"eDocTaxforms": false
}
]
This list is a strongly typed object with these properties:
public int AccountNumber { get; set; }
public bool? eDocConfirms { get; set; }
public bool? eDocStatements { get; set; }
public bool? eDocTaxforms { get; set; }
Using LINQ, I'd like to turn it into a list that looks like this:
[
{
"AccountNumber": 1234,
"EDocumentTypeName ": "Confirms"
},
{
"AccountNumber": 1234,
"EDocumentTypeName": "Statements"
}
]
This new list will a list of a different type:
public class DeliveryPreference
{
public int AccountNumber { get; set; }
public string EDocumentTypeName { get; set; }
}
Note that Taxforms was not included in the new list because it was set to false in the first list.
I know I could easily do this with some loops, but I would prefer using LINQ.
I understand that Stack Overflow prefers that I show what I have tried, but I am having trouble wrapping my brain around this.

For this case I would use additional function
public static IEnumerable<string> GetTrueProperties(Data t)
{
if (t.eDocConfirms == true) yield return "Confirms";
if (t.eDocStatements == true) yield return "Statements";
if (t.eDocTaxForms == true) yield return "Tax";
}
simply because it is an object and not a dictionary; else you could dynamically select properties which are true(or you could use reflection, but I think it would be too much here, since you have strongly typed object).
then it would look like
var list = new List<Data> {
new Data
{
AccountNumber = 1,
eDocConfirms = true,
eDocStatements = true,
eDocTaxForms = false
}
};
list.SelectMany(item => GetTrueProperties(item).Select(p => new DeliveryPreference
{
AccountNumber = item.AccountNumber,
EDocumentTypeName = p
}));

This is very ugly code, but it works. It should be easy to comprehend. Reflection can be extracted to a new function.
using System;
using System.Linq;
public class Program
{
public class Account {
public int AccountNumber { get; set; }
public bool? eDocConfirms { get; set; }
public bool? eDocStatements { get; set; }
public bool? eDocTaxforms { get; set; }
}
public class DeliveryPreference
{
public int AccountNumber { get; set; }
public string EDocumentTypeName { get; set; }
}
public static void Main()
{
var acc = new Account {
AccountNumber = 10,
eDocConfirms = true,
eDocStatements = false,
eDocTaxforms = true
};
var transformed = acc.GetType()
.GetProperties()
.Where(p => p.PropertyType == typeof(bool?)
&& ((bool?)p.GetValue(acc)).HasValue
&& ((bool?)p.GetValue(acc)).Value)
.Select(p => new DeliveryPreference {
AccountNumber = acc.AccountNumber,
EDocumentTypeName = p.Name.Substring(4)
});
foreach (var t in transformed) {
Console.WriteLine(t.AccountNumber);
Console.WriteLine(t.EDocumentTypeName);
}
}
}

Using a Parameter to Call a Class in C#

I have got a method with a single parameter of string class that I need to use to access another class in my project.
The following will be what I want it to do. Note that this syntax gives errors.
public string getId(string name) {
string Id = name.GetId();
return Id;
}
Assuming that the user enters "Joe" as the name, one would go to the class Joe.cs, which looks like this.
public class Joe {
public string Id = 32;
public string GetId() {
return Id;
}
}
What I want to happen here is for the first method to be able to get the GetId method from Joe if Joe is entered as a parameter. How would I do this? Thank you all.

This might point you in a better direction
The idea is to have a class called User that holds user information (funnily enough)
This way you can have a list of users (not a class for each one), as such you can easily look up a user and mess with them as much as you want
public class User
{
public string UserName { get; set; }
public string FavoriteColor { get; set; }
}
public class Program
{
// A List to hold users
private static List<User> _users = new List<User>();
private static void Main(string[] args)
{
// lets add some people
_users.Add(new User() { UserName = "Bob",FavoriteColor = "Red" });
_users.Add(new User() { UserName = "Joe", FavoriteColor = "Green" });
_users.Add(new User() { UserName = "Fred", FavoriteColor = "Blue" });
// use a linq query to find someone
var user = _users.FirstOrDefault(x => x.UserName == "Bob");
// do they exist?
if (user != null)
{
// omg yay, gimme teh color!
Console.WriteLine(user.FavoriteColor);
}
}
}
Output
Red
You can take it a step further and ask the user to look up other users (what a time to be a alive!)
Console.WriteLine("Enter a user (case sensitive)");
var userName = Console.ReadLine();
var user = _users.FirstOrDefault(x => x.UserName == userName);
if (user != null)
{
Console.WriteLine(user.FavoriteColor);
}
else
{
Console.WriteLine("Game over, you failed");
}
Console.ReadLine();

You could build a Class that can contain the details you want to store, then build a Manager class that exposes public methods that can extract informations from the stored objects:
public class Friend : IComparable<Friend>
{
public Friend() { }
public int ID { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public int FriendshipLevel { get; set; }
int IComparable<Friend>.CompareTo(Friend other)
{
if (other.FriendshipLevel > this.FriendshipLevel) return -1;
else return (other.FriendshipLevel == this.FriendshipLevel) ? 0 : 1;
}
}
public class MyFriends : List<Friend>
{
public MyFriends() { }
public int? GetID(string FriendName)
{
return this.Where(f => f.FirstName == FriendName).FirstOrDefault()?.ID;
}
public Friend GetFriendByID(int FriendID)
{
return this.Where(f => f.ID == FriendID).FirstOrDefault();
}
}
Build a sample class:
MyFriends myFriends = new MyFriends()
{
new Friend() { ID = 32, FirstName = "Joe", LastName = "Doe", FriendshipLevel = 100},
new Friend() { ID = 21, FirstName = "Jim", LastName = "Bull", FriendshipLevel = 10},
new Friend() { ID = 10, FirstName = "Jack", LastName = "Smith", FriendshipLevel = 50},
};
Then you can extract informations on single/multiple objects using the public methods of the "Manager" class:
int? ID = myFriends.GetID("Joe");
if (ID.HasValue) // Friend Found
Console.WriteLine(ID);
//Search a friend by ID
Friend aFriend = myFriends.GetFriendByID(32);
if (aFriend != null)
Console.WriteLine($"{aFriend.FirstName} {aFriend.LastName}");
Or you can use LINQ to get/aggregate the required informations directly if there isn't a public method that fits:
// Get your best friends using LINQ directly
List<Friend> goodFriends = myFriends.Where(f => f.FriendshipLevel > 49).ToList();
goodFriends.ForEach((f) => Console.WriteLine($"{f.FirstName} {f.LastName}"));
//Best friend
Friend bestFriend = myFriends.Max();

With respect to your Question : GetId method from Joe if Joe is entered as a
parameter.
You can achieve that in the following ways also:
2. Method Using Named Method.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace Problem
{
// Simple Model Class.
public class Person
{
public int Id { get; set; }
public string Name { get; set; }
}
class Program
{
// Delegate.
public delegate string PersonHandler(Person person);
static void Main(string[] args)
{
List<Person> _persons = new List<Person>()
{
new Person(){Id=1,Name="Joe"},
new Person(){Id=2,Name="James"},
new Person(){Id=3,Name="Nick"},
new Person(){Id=4,Name="Mike"},
new Person(){Id=5,Name="John"},
};
PersonHandler _personHandler = new PersonHandler(GetIdOfPerson);
IEnumerable<string> _personIds = _persons.Select(p => _personHandler.Invoke(p));
foreach (var id in _personIds)
{
Console.WriteLine(string.Format("Id's : {0}", id));
}
}
// This is the GetId Method.
static string GetIdOfPerson(Person person)
{
string Id = person.Id.ToString();
return Id;
}
}
}
2. Method Using Anonymous Moethod.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace Problem
{
// Simple Model Class.
public class Person
{
public int Id { get; set; }
public string Name { get; set; }
}
class Program
{
// Delegate.
public delegate string PersonHandler(Person person);
static void Main(string[] args)
{
List<Person> _persons = new List<Person>()
{
new Person(){Id=1,Name="Joe"},
new Person(){Id=2,Name="James"},
new Person(){Id=3,Name="Nick"},
new Person(){Id=4,Name="Mike"},
new Person(){Id=5,Name="John"},
};
PersonHandler _personHandler = delegate(Person person)
{
string id = person.Id.ToString();
return id;
};
// Retrieving all person Id's.
IEnumerable<string> _personIds = _persons.Select(p => _personHandler.Invoke(p));
foreach (var id in _personIds)
{
Console.WriteLine(string.Format("Id's : {0}", id));
}
}
}
}
2. Method Using a Lambda Expression.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace Problem
{
// Simple Model Class.
public class Person
{
public int Id { get; set; }
public string Name { get; set; }
}
class Program
{
// Delegate.
public delegate string PersonHandler(Person person);
static void Main(string[] args)
{
List<Person> _persons = new List<Person>()
{
new Person(){Id=1,Name="Joe"},
new Person(){Id=2,Name="James"},
new Person(){Id=3,Name="Nick"},
new Person(){Id=4,Name="Mike"},
new Person(){Id=5,Name="John"},
};
PersonHandler _personHandler = (Person person) => person.Id.ToString();
IEnumerable<string> _personIds = _persons.Select(p => _personHandler.Invoke(p));
foreach (var id in _personIds)
{
Console.WriteLine(string.Format("Id's : {0}", id));
}
}
}
}
Output:

how do i create a Generic List for the class batch and inside class batch i want to put student class information

Here I want to student class inside batch class and use them using the List class, how do I create object of both the classes for List...
Example if I want to find the name of a student from the batch how do I do it...
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace Challenge
{
class student
{
string student_name;
int age, rollnumber;
public student(string student_name, int age, int rollnumber)
{
this.age = age;
this.student_name = student_name;
this.rollnumber = rollnumber;
}
}
class batch
{
string batch_name;
int fees, duration;
public batch(string batch_name,int fees,int duration)
{
this.batch_name = batch_name;
this.fees = fees;
this.duration = duration;
}
}
class Program
{
static void Main(string[] args)
{
List<batch> obj = new List<batch>();
}
}
}

It is not very clear what you want to do, but I will try to help. From what I can understand, you want to create a collection of Batches, where every Batch contains a collection of Students.
Declare a List<Student> property in the Batch class:
public class Batch
{
public string Name { get; set; }
public int Fee { get; set; }
public int Duration { get; set; }
public List<Student> Students { get; set; }
}
public class Student
{
public string Name { get; set; }
public int RollNumber { get; set; }
// Date of birth instead of age, as explained in comment by Dour High Arch.
public DateTime DateOfBirth { get; set; }
}
You may now create a list of batches by:
var batches = new List<Batch>
{
new Batch
{
Name = "Batch 1",
Duration = 100,
Fee = 200,
Students = new List<Student>
{
new Student
{
Name = "Student 1",
DateOfBirth = DateTime.Today,
RollNumber = 1
},
new Student
{
Name = "Student 2",
DateOfBirth = DateTime.Today,
RollNumber = 2
}
}
}
};
Your batches list can be iterated as:
foreach (var batch in batches)
{
Console.WriteLine($"Batch: {batch.Name}");
foreach (var student in batch.Students)
{
Console.WriteLine($"Student: {student.Name}");
}
}

Get Collections from object using reflection and getCount (.net 4)

I have a requirement to reflect on a object get all properties that are collections and
1)GetCount for each collection
2)GetTotalCount (allCollectionCount)
3)Call a method with this collection.
Below is what I have done so far with a made up noddy structure for semplicity.
I am stuck in how to call this method and how to get count for collection.
Any suggestions?
using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Text;
namespace ConsoleApplication2
{
class Program
{
static void Main()
{
var request = GetDataRequest();
//Get all properties
List<PropertyInfo> propInfoList =
new List<PropertyInfo>(request.GetType().GetProperties(BindingFlags.Instance | BindingFlags.Public));
//Get collections only
var myClassCollections=propInfoList.Where(xxx => xxx.PropertyType.GetInterfaces().Any(x => x == typeof (IEnumerable))).ToList();
var totalCountForAllCollections=????
foreach (var col in myClassCollections)
{
//How do I call my Method DoSomething
// DoSomething<?>(col.?????)
}
}
public void DoSomething<T>(List<T> objectCollection)
{
//etc...
}
private static DataRequest GetDataRequest()
{
DataRequest request = new DataRequest();
request.Addresses.Add(new Address
{
Id = 1,
City = "London",
Postcode = "32131",
Street = "London Road"
});
request.Addresses.Add(new Address
{
Id = 2,
City = "NewYork",
Postcode = "3432",
Street = "NewYork Road"
});
request.Customers.Add(new Customer
{
Id = 1,
Name = "Jo",
Surname = "Bloggs",
});
request.Customers.Add(new Customer
{
Id = 1,
Name = "Jon",
Surname = "Bloggs2",
});
request.Customers.Add(new Customer
{
Id = 1,
Name = "Jonny",
Surname = "Bloggs3",
});
return request;
}
}
public class DataRequest
{
public DataRequest()
{
Customers = new List<Customer>();
Orders = new List<Order>();
Addresses = new List<Address>();
}
public List<Customer> Customers { get; set; }
public List<Order> Orders { get; set; }
public List<Address> Addresses { get; set; }
}
public class Customer
{
public int Id { get; set; }
public string Name { get; set; }
public string Surname { get; set; }
}
public class Order
{
public int Id { get; set; }
public string Name { get; set; }
public string OrderNo { get; set; }
}
public class Address
{
public int Id { get; set; }
public string Street { get; set; }
public string City { get; set; }
public string Postcode { get; set; }
}
}

quick and dirty, here you go...
// ..
static class Program
{
static void Main()
{
var request = GetDataRequest();
//Get propertyValues for properties that are enumerable (i.e. lists,arrays etc)
var collectionProperties = request.GetType()
.GetProperties(BindingFlags.Instance | BindingFlags.Public)
.Where(propertInfo => propertInfo.PropertyType.GetInterfaces().Any(x => x == typeof(IEnumerable)))
.Select(p => p.GetValue(request, null))
.Cast<IEnumerable<object>>().ToList();
var totalCountForAllCollections = 0;
// iterate through the list of propertyValues
foreach (var collectionPropertyValue in collectionProperties)
{
totalCountForAllCollections += collectionPropertyValue.Count();
collectionPropertyValue.DoSomething();
}
System.Console.WriteLine("The total count for all collections is : {0}", totalCountForAllCollections);
System.Console.WriteLine("press any key to exit");
System.Console.ReadLine();
}
public static void DoSomething<T>(this IEnumerable<T> objectCollection)
{
//etc...
// N.B. you will have to use typeof(T) to implement logic specific to the type
// If the logic in this method is non-specific to the typeof(T) then Implement logic accordingly
System.Console.WriteLine("The type of the collection is: {0}", objectCollection.GetType());
System.Console.WriteLine("The count of items in this collection is:{0}", objectCollection.Count());
}
// ..
}
// ..

Get values from one list inside one list using lambda expression

i am new to lambda expression so i try to solve one problem .but i can't. so can anyone suggest solution for this.
i have one class customer. inside i created another 3 class and create observable collection for 3 classes.i create one observable collection for this customer
ObservableCollection<Customer> customer2;
public class Customer
{
public string CusName { get; set; }
public int CusAge { get; set; }
public ObservableCollection<Bankdetails> bankdetails;
public ObservableCollection<order> orderlist;
public ObservableCollection<orderdetails> orderdetailslist;
public class Bankdetails
{
public string Bankaccno { get; set; }
public string bankname { get; set; }
public int bankid { get; set; }
}
public class order
{
public string ordername { get; set; }
public string orderid { get; set; }
}
public class orderdetails
{
public string orderid { get; set; }
public string itemname { get; set; }
public int itemqty { get; set; }
}
}
i write one linq query for getting values from customer2.anyhow its working .like this i tried to write one lambda query but i can't.
here i adding some values to observable collection.
customer2 = new ObservableCollection<Customer>
{
new Customer()
{
CusName="nixon",CusAge=24,
bankdetails=new ObservableCollection<Customer.Bankdetails>
{
new Customer.Bankdetails()
{
bankid=12,bankname="axis",Bankaccno="09876534"
}
},
orderlist=new ObservableCollection<Customer.order>
{
new Customer.order
{
orderid="Od123",ordername="Express"
}
},
orderdetailslist=new ObservableCollection<Customer.orderdetails>
{
new Customer.orderdetails
{
orderid="Od123",itemname="cpu",itemqty=5
}
}
}
};
this is my linq query
var customer1 = from cus in customer2
from bank in cus.bankdetails
from ord in cus.orderlist
from orddet in cus.orderdetailslist
where ord.orderid == orddet.orderid
select new
{
cus.CusAge,cus.CusName,
bank.Bankaccno,bank.bankid,bank.bankname,
ord.ordername,
orddet.itemname,orddet.itemqty
};
then what will be the lambda query.pls anyone suggest .

Matt's solution extended with the where from the question would be:
var xxx = customer2.SelectMany(cus =>
cus.bankdetails.SelectMany(bank =>
cus.orderlist.SelectMany(ord =>
cus.orderdetailslist.Where(orddet => orddet.orderid == ord.orderid)
.Select(orddet => new
{
cus.CusAge,
cus.CusName,
bank.Bankaccno,
bank.bankname,
orddet.itemname,
orddet.itemqty
}
)
)
)
);

var xxx = customer2.SelectMany(cus =>
cus.bankdetails.SelectMany(bank =>
cus.orderlist.SelectMany(ord =>
cus.orderdetailslist.Select(orddet => new
{
cus.CusAge,
cus.CusName,
bank.Bankaccno,
bank.bankname,
orddet.itemname,
orddet.itemqty
}
)
)
)
);