Csharp/CSharp Tutorial/Data Structure/Dictionary
Add to dictionary
<source lang="csharp">using System; using System.Collections.Generic;
public class Tester { static void Main() { Dictionary<string, string> Dictionary = new Dictionary<string, string>(); Dictionary.Add("1", "J"); Dictionary.Add("2", "S"); Dictionary.Add("3", "D"); Dictionary.Add("4", "A"); Console.WriteLine(Dictionary["1"]); } }</source>
Dictionary Demo
<source lang="csharp">using System; using System.Collections.Generic; using System.ruponentModel; using System.Text.RegularExpressions;
class DictionaryDemo { static Dictionary<string,int> CountWords(string text) { Dictionary<string,int> frequencies = new Dictionary<string,int>(); string[] words = Regex.Split(text, @"\W+"); foreach (string word in words) { if (frequencies.ContainsKey(word)) { frequencies[word]++; } else { frequencies[word] = 1; } } return frequencies; } static void Main() { string text = "this is a test"; Dictionary<string, int> frequencies = CountWords(text); foreach (KeyValuePair<string, int> entry in frequencies) { string word = entry.Key; int frequency = entry.Value; Console.WriteLine("{0}: {1}", word, frequency); } } }</source>
Use the keys to obtain the values from a generic Dictionary<TK, TV>
<source lang="csharp">using System; using System.Collections.Generic;
class MainClass {
public static void Main() { Dictionary<string, double> dict = new Dictionary<string, double>(); // Add elements to the collection. dict.Add("A", 7); dict.Add("B", 5); dict.Add("C", 4); dict.Add("D", 9); // Get a collection of the keys (names). ICollection<string> c = dict.Keys; foreach(string str in c) Console.WriteLine("{0}, Salary: {1:C}", str, dict[str]); }
}</source>
A, Salary: $7.00 B, Salary: $5.00 C, Salary: $4.00 D, Salary: $9.00