Exercise to learn about common c # data types. Dictionaries.

Practice: Stock Purchase Dictionaries Setup mkdir -p ~/workspace/csharp/exercises/dictionaries && cd $_ dotnet new console References C# dictionaries Dictionary in C# Interactive C# Dictionaries Instructions A block of publicly traded stock has a variety of attributes, we'll look at a few of them. A stock has a ticker symbol and a company name. Create a simple dictionary with ticker symbols and company names in the Main method.

Example Dictionary<string, string> stocks = new Dictionary<string, string>(); stocks.Add("GM", "General Motors"); stocks.Add("CAT", "Caterpillar"); // Add a few more of your favorite stocks To find a value in a Dictionary, you can use square bracket notation much like JavaScript object key lookups.

string GM = stocks["GM"]; <--- "General Motors" Next, create a list to hold stock purchases by an investor. The list will contain dictionaries.

List<Dictionary<string, double>> purchases = new List<Dictionary<string, double>>(); Then add some purchases.

Example purchases.Add (new Dictionary<string, double>(){ {"GE", 230.21} }); purchases.Add (new Dictionary<string, double>(){ {"GE", 580.98} }); purchases.Add (new Dictionary<string, double>(){ {"GE", 406.34} });

// Add more purchases for each stock Create a total ownership report that computes the total value of each stock that you have purchased. This is the basic relational database join algorithm between two tables.

Helpful Links: ContainsKey, Add

/* Define a new Dictionary to hold the aggregated purchase information. - The key should be a string that is the full company name. - The value will be the total valuation of each stock

From the three purchases above, one of the entries
in this new dictionary will be...
    {"General Electric", 1217.53}

Replace the questions marks below with the correct types.

*/ Dictionary stockReport = new Dictionary();

/* Iterate over the purchases and record the valuation for each stock. */ foreach (Dictionary<string, double> purchase in purchases) { foreach (KeyValuePair<string, double> stock in purchase) { // Does the full company name key already exist in the stockReport?

    // If it does, update the total valuation

    /*
        If not, add the new key and set its value.
        You have the value of "GE", so how can you look
        the value of "GE" in the `stocks` dictionary
        to get the value of "General Electric"?
    */
}

} Now that the report dictionary is populated, display the final results.

foreach(KeyValuePair item in stockReport) { Console.WriteLine($"The position in {display the key} is worth {display the value}"); }