CODE:

using System;
using System.Collections.Generic;
using System.IO;

namespace RecordStuffAddUpdateLookup
{
class Program
{
static void Main(string[] args)
{

List<Student>list=new List<Student>();
using (StreamReader reader = new StreamReader("..//..//TextFile1.txt"))
{
while (true)
{
string line = reader.ReadLine();
if (line == null)
{
break;
}

string []arr=line.Split(',');

Student obj=new Student();

obj.name=arr[0];
obj.address=arr[1];
obj.id=Convert.ToDouble(arr[2]);
obj.phoneNumbers=Convert.ToDouble(arr[3]);
obj.courses=arr[4];

list.Add(obj);
}
}

string check="";

do
{
Console.WriteLine("1.Add");
Console.WriteLine("2.Update");
Console.WriteLine("3.Lookup");
Console.WriteLine("4.Exit");
Console.WriteLine("Choose your number");

switch (Console.ReadLine())
{
case "1":

Student obj = new Student();
Console.WriteLine("Enter the name");
obj.name = Console.ReadLine();
Console.WriteLine("Enter the address");
obj.address = Console.ReadLine();
Console.WriteLine("Enter the id");
obj.id = Convert.ToDouble(Console.ReadLine());
Console.WriteLine("Enter the phoneNumber");
obj.phoneNumbers = Convert.ToDouble(Console.ReadLine());
Console.WriteLine("Enter the courses");
obj.courses = Console.ReadLine();
list.Add(obj);
Console.WriteLine("Added");

break;
case "2":

Console.WriteLine("Enter the name you want to edit");
string name = Console.ReadLine();

for (int i = 0; i < list.Count; i++)
{
if (list[i].name == name)
{
Console.WriteLine("Enter the address");
list[i].address = Console.ReadLine();
Console.WriteLine("Enter the id");
list[i].id = Convert.ToDouble(Console.ReadLine());
Console.WriteLine("Enter the phoneNumber");
list[i].phoneNumbers = Convert.ToDouble(Console.ReadLine());
Console.WriteLine("Enter the courses");
list[i].courses = Console.ReadLine();
}

}

break;

case "3":
Console.WriteLine("Enter the name you want to search");

string Name = Console.ReadLine();
for (int i = 0; i < list.Count; i++)
{
if (list[i].name == Name)
{
Console.WriteLine("Name is " + list[i].name);
Console.WriteLine("Address is " + list[i].address);
Console.WriteLine("id is " + list[i].id);
Console.WriteLine("phone number is " + list[i].phoneNumbers);
Console.WriteLine("Courses is " + list[i].courses);
}
}

break;

case "4":
check = "q";

break;

}
}
while (check != "q");

using (StreamWriter writer = new StreamWriter("..//..//TextFile1.txt"))
{

for(int i=0;i<list.Count;i++)
{
writer.WriteLine(list[i].name + "," + list[i].address + "," + list[i].id + "," + list[i].phoneNumbers + "," + list[i].courses);
writer.WriteLine(Environment.NewLine);
}

}

}
}

class Student
{
public string name;
public string address;
public double id;
public double phoneNumbers;
public string courses;

}
}