Hi$,$ I need your help in C# please. I need to complete the code below for practice but I am not familiar with it yet.

Here is the code below.

using System;

using System.Collections.Generic;

namespace GLA$\_01$

$\{$

class Contact

$\{$

public string Name $\{$ get; set; $\}$

public long Phone $\{$ get; set; $\}$

$\}$

class Program

$\{$

public static void DisplayListAll$($List myList$)$

$\{$

if $($myList$.$Count $==0)$

$\{$

Console.WriteLine$("$List is empty!"$)$;

$\}$

else

$\{$

Console.WriteLine$("$

All Contacts from the phonebook:

$")$;

foreach $($var item in myList$)$

$\{$

Console.WriteLine$("$Name: $\{0\},$ Phone: $\{1\}",$ item.Name, item.Phone$)$;

$\}$

$\}$

$\}$

public static string ConvertToNameCase$($string name$)$

$\{$

return name$[0].$ToString$().$ToUpper$()+$ name.Substring$(1)$;

$\}$

$//$Complete the ToDo Methods, additionally, you may also add new methods, if you need.

public static void DisplayAllContactsOfAUserName$($List myList$)//$you may change parameters if required

$\{$

$//$ToDo

$//$All contacts of a single user name

$//$if an user have two contact number, print user name once followed by contact numbers

$//$please see provided input$/$output for the formatting

$\}$

public static Contact FindContactGivenAPhone$($List myList, long phone$)$

$\{$

$//$ToDo: remove the return null statement and complete the method

$//$Note: this method should return a Contact object

return null;

$\}$

public static List FindAllContactsOfAGivenName$($List myList, string name$)$

$\{$

$//$ToDo: remove the return null statement and complete the method

$//$Note: this method returns a List of Contacts; even if a single contact record exists for the given name

return null;

$\}$

$//$ToDo Methods

static void Main$($string$[]$ args$)$

$\{$

List contactList $=$ new List$()$;

string command;

do

$\{$

Console.WriteLine$("$

Enter a command: $")$;

command $=$ Console.ReadLine$()$;

command $=$ command.ToLower$()$;

while $($command$.$Contains$(""))$ command $=$ command.Replace$("","")$;

command $=$ command.Trim$()$;

var split $=$ command.Split$($null$)$;

if $($split$.$Length $==1)$

$\{$

if $($split$[0]==$ "exit"$)$

$\{$

break;

$\}$

else if $($split$[0]==$ "findall"$)$

$\{$

DisplayListAll$($contactList$)$;

$\}$

$\}$

else if $($split$.$Length $==0)$ continue;

else if $($split$[0]==$ "add"$)$

$\{$

for $($int i $=1$; i $<$ split.Length $-1$; i$++)$

$\{$

split$[$i$]=$ ConvertToNameCase$($split$[$i$])$;

$\}$

contactList.Add$($new Contact$()\{$ Name $=$ string.Join$("",$ split, $1,$ split.Length $-2),$ Phone $=$ long.Parse$($split$[$split$.$Length $-1])\})$;

$\}$

else if $($split$[0]==$ "find"$)$

$\{$

$//$ToDo

$//$Complete this block

$//$separate the correctly formatted name from the 'split' array

$//$choose the method to find all contacts when given a user name

$//$choose method to display all contacts of that user name

$//$NB: A user name can have one or more contact numbers

$\}$

else if $($split$[0]==$ "update"$)$

$\{$

$//$ToDo update

$//$ToDo

$//$Complete this block

$//$separate old number from the 'split' array

$//$choose the method to find a contact when given the old phone number

$//$remove the contact containing the old phone number from the contactList

$//$extract the correctly formatted new user name and the from the 'split' array

$//$Add a new contact object into the contactList with and

$\}$

else

$\{$

Console.WriteLine$("$Unknown command!

Please enter command in correct format..."$)$;

$\}$

$\}$ while $($true$)$;

$\}$

$\}$

$\}$