Dictionaries

In the previous section, you got to know the Hashtable class as a non-generic variant of the hash table-related classes. However, it has a significant limitation, because it does not allow you to specify a type of a key and a value. Both the Key and Value properties of the DictionaryEntry class are of the object type. Therefore, you need to perform boxing and unboxing operations, even if all keys and values have the same type.

If you want to benefit from the strongly typed variant, you can use the Dictionary generic class, which is the main subject of this section of the chapter.

First of all, you should specify two types namely, a type of a key and a value, while creating an instance of the Dictionary class. Moreover, it is possible to define initial content of the dictionary using the following code:

Dictionary<string, string> dictionary = 
    new Dictionary<string, string> 
{ 
    { "Key 1", "Value 1" }, 
    { "Key 2", "Value 2" } 
}; 

In the preceding code, a new...