/*
* 1. A dictionary is a collection of (key, value) pair.
* 2. Dictionary class is present in System.Collection.Generic namespace.
* 3. When creating a dictionary, we need to specify the type for key and value.
* 4. Dictionary provides fast lookups for value using keys.
* 5. Keys in the dictionary must be unique.
*
* 6. In this chapter, we will learn the fllowing methods of dictonary class.
* a. TryGetValue()
* b. Count()
* c. Remove()
* d. Clear()
* e. Using LINQ extension methods with Dictonary.
* f. Different ways to convert an Array or List into a dictonary.
*/
static void Main(string[] args)
{
Customer customer1 = new Customer()
{
ID = 101, Name = "Anand Dev", Salry = 4000
};
Customer customer2 = new Customer()
{
ID = 102, Name = "Praveen", Salry = 5000
};
Customer customer3 = new Customer()
{
ID = 103, Name = "Uttam", Salry = 8000
};
Dictionary <int, Customer> dCustomers = new Dictionary <int, Customer>();
dCustomers.Add(customer1.ID, customer1);
dCustomers.Add(customer2.ID, customer2);
dCustomers.Add(customer3.ID, customer3);
#region a. TryGetValue() method.
Customer cust1 = new Customer();
if (dCustomers.TryGetValue(101, out cust1))
{
Console.WriteLine("ID = {0}, Name = {1}, Sal = {2}", cust1.ID, cust1.Name, cust1.Salry);
}
else
{
Console.WriteLine("Key not found");
}
#endregion
#region b. Count() method.// Count is Linq extension method present in System.Linq namespace.
int custCount = dCustomers.Count();
Console.WriteLine("\nTotal number of items in dictionary are = {0}", custCount);
int custCount2 = dCustomers.Count(kvp => kvp.Value.Salry > 5000);
Console.WriteLine("\nCustomers having salary > 5000 = {0}", custCount2);
#endregion
#region c. Remove() method.
dCustomers.Remove(102);
Console.WriteLine("\nAfter removing one item");
foreach (KeyValuePair <int, Customer> custKeyValue in dCustomers)
{
Customer c = custKeyValue.Value;
Console.WriteLine("ID = {0}, Name = {1}, Sal = {2}", c.ID, c.Name, c.Salry);
Console.WriteLine("*******************************************************");
}
#endregion
#region d. Clear() method
dCustomers.Clear();
Console.WriteLine("\nNo item will be found after clear() of dictionary.");
foreach (KeyValuePair <int, Customer> custKeyValue in dCustomers)
{
Customer c = custKeyValue.Value;
Console.WriteLine("ID = {0}, Name = {1}, Sal = {2}", c.ID, c.Name, c.Salry);
Console.WriteLine("*******************************************************");
}
#endregion
#region e. Convert Array to Dictionary.
Customer[] customers = new Customer[3];
customers[0] = customer1;
customers[1] = customer2;
customers[2] = customer3;
Dictionary <int, Customer> dicCustomers = customers.ToDictionary(c => c.ID, c => c);
Console.WriteLine("\nConvert Array to Dictionary.");
foreach (KeyValuePair <int, Customer> kvp in dicCustomers)
{
Customer c = kvp.Value;
Console.WriteLine("ID = {0}, Name = {1}, Sal = {2}", c.ID, c.Name, c.Salry);
Console.WriteLine("*******************************************************");
}
#endregion
#region f. Convert List to Dictionary
List <Customer> listCustomers = new List <Customer>();
listCustomers.Add(customer1);
listCustomers.Add(customer2);
listCustomers.Add(customer3);
Dictionary <int, Customer> dicListCustomers = listCustomers.ToDictionary(c => c.ID, c => c);
Console.WriteLine("\nConvert List to Dictionary.");
foreach (KeyValuePair <int, Customer> kvp in dicListCustomers)
{
Customer c = kvp.Value;
Console.WriteLine("ID = {0}, Name = {1}, Sal = {2}", c.ID, c.Name, c.Salry);
Console.WriteLine("*******************************************************");
}
#endregion
Console.ReadKey();
}
/*
* 1. A dictionary is a collection of (key, value) pair.
* 2. Dictionary class is present in System.Collection.Generic namespace.
* 3. When creating a dictionary, we need to specify the type for key and value.
* 4. Dictionary provides fast lookups for value using keys.
* 5. Keys in the dictionary must be unique.
*
* 6. In this chapter, we will learn the fllowing methods of dictonary class.
* a. TryGetValue()
* b. Count()
* c. Remove()
* d. Clear()
* e. Using LINQ extension methods with Dictonary.
* f. Different ways to convert an Array or List into a dictonary.
*/
static void Main(string[] args)
{
Customer customer1 = new Customer() { ID = 101, Name = "Anand Dev", Salry = 4000 };
Customer customer2 = new Customer() { ID = 102, Name = "Praveen", Salry = 5000 };
Customer customer3 = new Customer() { ID = 103, Name = "Uttam", Salry = 8000 };
Dictionary<int, Customer> dCustomers = new Dictionary<int, Customer>();
dCustomers.Add(customer1.ID, customer1);
dCustomers.Add(customer2.ID, customer2);
dCustomers.Add(customer3.ID, customer3);
#region a. TryGetValue() method.
Customer cust1 = new Customer();
if (dCustomers.TryGetValue(101, out cust1))
{
Console.WriteLine("ID = {0}, Name = {1}, Sal = {2}", cust1.ID, cust1.Name, cust1.Salry);
}
else
{
Console.WriteLine("Key not found");
}
#endregion
#region b. Count() method.// Count is Linq extension method present in System.Linq namespace.
int custCount = dCustomers.Count();
Console.WriteLine("\nTotal number of items in dictionary are = {0}", custCount);
int custCount2 = dCustomers.Count(kvp => kvp.Value.Salry > 5000);
Console.WriteLine("\nCustomers having salary > 5000 = {0}", custCount2);
#endregion
#region c. Remove() method.
dCustomers.Remove(102);
Console.WriteLine("\nAfter removing one item");
foreach (KeyValuePair<int, Customer> custKeyValue in dCustomers)
{
Customer c = custKeyValue.Value;
Console.WriteLine("ID = {0}, Name = {1}, Sal = {2}", c.ID, c.Name, c.Salry);
Console.WriteLine("*******************************************************");
}
#endregion
#region d. Clear() method
dCustomers.Clear();
Console.WriteLine("\nNo item will be found after clear() of dictionary.");
foreach (KeyValuePair<int, Customer> custKeyValue in dCustomers)
{
Customer c = custKeyValue.Value;
Console.WriteLine("ID = {0}, Name = {1}, Sal = {2}", c.ID, c.Name, c.Salry);
Console.WriteLine("*******************************************************");
}
#endregion
#region e. Convert Array to Dictionary.
Customer[] customers = new Customer[3];
customers[0] = customer1;
customers[1] = customer2;
customers[2] = customer3;
Dictionary<int, Customer> dicCustomers = customers.ToDictionary(c => c.ID, c => c);
Console.WriteLine("\nConvert Array to Dictionary.");
foreach (KeyValuePair<int, Customer> kvp in dicCustomers)
{
Customer c = kvp.Value;
Console.WriteLine("ID = {0}, Name = {1}, Sal = {2}", c.ID, c.Name, c.Salry);
Console.WriteLine("*******************************************************");
}
#endregion
#region f. Convert List to Dictionary
List<Customer> listCustomers = new List<Customer>();
listCustomers.Add(customer1);
listCustomers.Add(customer2);
listCustomers.Add(customer3);
Dictionary<int, Customer> dicListCustomers = listCustomers.ToDictionary(c => c.ID, c => c);
Console.WriteLine("\nConvert List to Dictionary.");
foreach (KeyValuePair<int, Customer> kvp in dicListCustomers)
{
Customer c = kvp.Value;
Console.WriteLine("ID = {0}, Name = {1}, Sal = {2}", c.ID, c.Name, c.Salry);
Console.WriteLine("*******************************************************");
}
#endregion
Console.ReadKey();
}
