public static void Main()
{
customer c1 = new customer()
{
ID = 101,
Name = "Rich",
Salary = 5000
};
customer c2 = new customer()
{
ID = 110,
Name = "Joe",
Salary = 7000
};
customer c3 = new customer()
{
ID = 111,
Name = "Leslie",
Salary = 9000
};
//We first create the instances of the customers and then add them to the dictionary with the Key being their ID. The dictionary uses the ID as the
//key and the value we want to return is all the customer properties so we choose 'customer' as the value type.
Dictionary <int, customer> dictionaryCustomer = new Dictionary <int, customer>();
dictionaryCustomer.Add(c1.ID, c1);
dictionaryCustomer.Add(c2.ID, c2);
dictionaryCustomer.Add(c3.ID, c3);
//This checks if a dictionary already has this ID in there. This is prevent adding duplicates or other forms of key's
if (!dictionaryCustomer.ContainsKey(c1.ID))
{
dictionaryCustomer.Add(c1.ID, c3);
}
customer cust111 = dictionaryCustomer[111];
//Console.WriteLine("ID = {0}, Name = {1}, Salary = {2}", cust111.ID, cust111.Name, cust111.Salary);
//We want to iterate through all the combinations of the key/value that are stored in the dictionary called dictionaryCustomer and then we want to
//write the key along with the other info/properties of the customer.
foreach (KeyValuePair <int, customer> customerKeyValuePair in dictionaryCustomer)
{
Console.WriteLine("ID = {0}", customerKeyValuePair.Key);
customer cust = customerKeyValuePair.Value;
Console.WriteLine("ID = {0}, Name = {1}, Salary = {2}", cust.ID, cust.Name, cust.Salary);
Console.WriteLine("-------------------------------------------------------------------------------------");
}
//Lets say if we want to see if an ID exists in the database and we dont want the program to throw an exception, then we can use the TryGetValue
//method. This method is of type boolean so we can put it in an if statement. The first parameter is what we want to search and the second param
//is what we want to output
customer cust1;
if (dictionaryCustomer.TryGetValue(101, out cust1))
{
Console.WriteLine("ID = {0}, Name = {1}, Salary = {2}", cust1.ID, cust1.Name, cust1.Salary);
}
else
{
Console.WriteLine("Key not found");
}
//here we are converting an array to a dictionary
customer[] cust2 = new customer[3];
cust2[0] = c1;
cust2[1] = c2;
cust2[2] = c3;
Dictionary <int, customer> dict = cust2.ToDictionary(cus => cus.ID, cus => cus);
foreach (KeyValuePair <int, customer> kvp in dict)
{
Console.WriteLine("Key = {0}", kvp.Key);
customer cust3 = kvp.Value;
Console.WriteLine("ID = {0}, Name = {1}, Salary = {2}", cust3.ID, cust3.Name, cust3.Salary);
}
}
