Csharp/CSharp Tutorial/Data Structure/Dictionary

Add to dictionary

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"]);
        }
    }

Dictionary Demo

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);
            }
        }
    }

Use the keys to obtain the values from a generic Dictionary<TK, TV>

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]);  
  }  
}

A, Salary: $7.00
B, Salary: $5.00
C, Salary: $4.00
D, Salary: $9.00