C# 4 and .NET 4

252 ❘ ChaPTer 10 cOllectiOns
private readonly EmployeeId id;
public Employee(EmployeeId id, string name, decimal salary)
{
this.id = id;
this.name = name;
this.salary = salary;
}
}
public override string ToString()
{
return String.Format("{0}: {1, -20} {2:C}",
id.ToString(), name, salary);
}
code snippet DictionarySample/Employee.cs
In the Main() method of the sample application, a new Dictionary instance is created,
where the key is of type EmployeeId and the value is of type Employee. The constructor allocates a capacity
of 31 elements. Remember, the capacity is based on prime numbers. However, when you assign a value
that is not a prime number, you don’t need to worry. The Dictionary class itself takes the
next prime number that follows the integer passed to the constructor to allocate the capacity. The employee
objects and IDs are created and added to the dictionary with the Add() method. Instead of using the Add()
method, you can also use the indexer to add keys and values to the dictionary, as shown with the employees
Dale and Jeff:
static void Main()
{
var employees = new Dictionary(31);
var idKyle = new EmployeeId("T3755");
var kyle = new Employee(idKyle, "Kyle Bush", 5443890.00m);
employees.Add(idKyle, kyle);
Console.WriteLine(kyle);
var idCarl = new EmployeeId("F3547");
var carl = new Employee(idCarl, "Carl Edwards", 5597120.00m);
employees.Add(idCarl, carl);
Console.WriteLine(carl);
var idJimmie = new EmployeeId("C3386");
var jimmie = new Employee(idJimmie, "Jimmie Johnson", 5024710.00m);
employees.Add(idJimmie, jimmie);
Console.WriteLine(jimmie);
var idDale = new EmployeeId("C3323");
var dale = new Employee(idDale, "Dale Earnhardt Jr.", 3522740.00m);
employees[idDale] = dale;
Console.WriteLine(dale);
var idJeff = new EmployeeId("C3234");
var jeff = new Employee(idJeff, "Jeff Burton", 3879540.00m);
employees[idJeff] = jeff;
Console.WriteLine(jeff);
code snippet DictionarySample/Program.cs
After the entries are added to the dictionary, inside a while loop employees are read from the dictionary.
The user is asked to enter an employee number to store in the variable userInput. The user can exit the
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