[C#][TuT]How to use Dictionaries! - Printable Version +- Computer Tech (https://computertech.createmybb3.com) +-- Forum: Programming (https://computertech.createmybb3.com/forumdisplay.php?fid=6) +--- Forum: .Net Programming (https://computertech.createmybb3.com/forumdisplay.php?fid=8) +--- Thread: [C#][TuT]How to use Dictionaries! (/showthread.php?tid=101) |
[C#][TuT]How to use Dictionaries! - Ethereal - 01-15-2011 A dictionary is basically a database that you can easily access within your code. It has two variables - The key, and the value. You can access the value via a lookup utilizing the key. The following code is the syntax for declaring a new dictionary: [code] Dictionary<varType1,varType2> DicName = new Dictionary<varType1,varType2>(); [/code] For example: [code] private Dictionary<String, String> _keySettings = new Dictionary<String,String>(); [/code] NOTE* You can use the class, rather than the type. We can add values to our dictionary very easily: [code] DicName.Add(var1, var2) [/code] For example: [code] _keySettings.Add(kname, kval); [/code] This will be our first entry in our Dictionary. We can check how many values we have in our Dictionary with the code: [code] DicName.Count(); [/code] When we wish to access the data contained inside our Dictionary, we can call a lookup with the key as a parameter. This will return the value that the key corresponds to: [code] DicName[key]; [/code] And an example for outputting the values stored in the Dictionary into a listbox is: [code] foreach(string s in GetDictionaryKeys()) { listBox1.Items.Add(s); } public string[] GetDictionaryKeys() { return _keySettings.Values.ToArray(); } [/code] Now we are past the boring bit. You may ask where you would use this over an array, or other variable type? I personally first used this to hold the variable data for a program that allows you to manipulate a CS:S config. I read text from a file, parsed it and then added it into a Dictionary. The Dictionary data can then be passed to another form, for you to access as you please. Then, in a second form, I allowed new values to be entered changing the keybinding, and re-wrote the dictionary. Lookups were then used to re-write the config, with the new configuration settings. I have also used this as a lookup to convert characters/numeric values for my private encryption methods. This is just one example of implementing a Dictionary. Your use of it is limited only by your imagination. RE: [C#][TuT]How to use Dictionaries! - Ironside - 01-15-2011 Thank you for another excellent tutorial. |