About
In this code snippet, we’ll take a look at dictionaries in C#.
Dictionaries can hold a collection of objects and are similar to lists. But unlike lists, the objects stored in the dictionary are paired with a key. That key can be used to access the object in the collection.
Now let’s look the code below to see how to use dictionaries.
Code:
using System;
using System.Collections.Generic;
namespace Dictionary
{
class Program
{
static void Main(string[] args)
{
//Dictionary<> uses a key - value pair unlike List<>
//Dictionary<(key data type), (value data type)>
Dictionary<string, string> myDictionary = new Dictionary<string, string>();
//Add an item by first adding a key and than the value that will be referenced by the key.
myDictionary.Add("One", "I am first.");
myDictionary.Add("Two", "I am second.");
myDictionary.Add("Three", "I am third.");
//Show item in dictionary.
showDictionaryItems(myDictionary);
//Remove item by key.
myDictionary.Remove("Two");
//Show item in dictionary.
showDictionaryItems(myDictionary);
//Try to get the value by key.
string value = "";
if (myDictionary.TryGetValue("One", out value))
{
Console.WriteLine(value);
}
//Check if the key exists.
if (myDictionary.ContainsKey("One"))
{
Console.WriteLine("Key exists.");
}
else
{
Console.WriteLine("Key doesn't exist.");
}
//Clear the items.
myDictionary.Clear();
//Show item in dictionary.
showDictionaryItems(myDictionary);
Console.ReadLine();
}
public static void showDictionaryItems(Dictionary<string, string> myDictionary)
{
//Get the key and value of each item in the list.
foreach (var item in myDictionary)
{
Console.WriteLine(item.Key + ": " + item.Value);
}
Console.WriteLine("");
}
}
} Resulting output:
