Introduction
A dictionary
type represents a collection of keys and values pair of data.
The
Dictionary class defined in the System.Collections.Generic namespace is a
generic class and can store any data types in a form of keys and values. Each
key must be unique in the collection. Before you use the Dictionary class in
your code, you must import the System.Collections.Generic namespace using the
following line.
using System.Collections.Generic;
Creating a Dictionary
The Dictionary class constructor takes a key data type and a
value data type. Both types are generic so it can be any .NET data type.
The following The Dictionary class is a generic class and can
store any data types. This class is defined in the code snippet creates a
dictionary where both keys and values are string types.
Dictionary<string,
string> EmployeeList = new Dictionary<string, string>();
The following code snippet adds items to the dictionary.
EmployeeList.Add("Mahesh
Chand", "Programmer");
EmployeeList.Add("Praveen
Kumar", "Project Manager");
EmployeeList.Add("Raj
Kumar", "Architect");
EmployeeList.Add("Nipun
Tomar", "Asst. Project
Manager");
EmployeeList.Add("Dinesh
Beniwal", "Manager");
The following code snippet creates a dictionary where the key
type is string and value type is short integer.
Dictionary<string,
Int16> AuthorList = new Dictionary<string, Int16>();
The following code snippet adds items to the dictionary.
AuthorList.Add("Mahesh
Chand", 35);
AuthorList.Add("Mike
Gold", 25);
AuthorList.Add("Praveen
Kumar", 29);
AuthorList.Add("Raj
Beniwal", 21);
AuthorList.Add("Dinesh
Beniwal", 84);
We can also limit the size of a dictionary. The following code
snippet creates a dictionary where the key type is string and value type is
float and total number of items it can hold is 3.
Dictionary<string,
float> PriceList = new
Dictionary<string,
float>(3);
The following code snippet adds items to the dictionary.
PriceList.Add("Tea",
3.25f);
PriceList.Add("Juice",
2.76f);
PriceList.Add("Milk",
1.15f);
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