Dictionary In C#

Introduction

Dictionary class represents a collection of key values pair of the data. This class is a generic type, so this class can store any type of data. It can be primitive data types or non-primitive data types. First of all, we will discuss about primitive data types, followed by discussing about non-primitive data types.

Act

We can Add, Remove, Clear other collection methods. The key is used for get the value from a Dictionary.

Primitive data types

The code snippet given below creates a Dictionary named “students”, where the keys are integer and the value is a string.

Dictionary<int, string> students = new Dictionary<int, string>();

Add the values into students of Dictionary.

students.Add(1, "Shamim");
students.Add(2, "Seam");
students.Add(3, "Mamun");

Read all the data.  

foreach (KeyValuePair<int, string> astudent in students)
      {
         Console.WriteLine("Key = {0}, Value = {1}",
         astudent.Key, astudent.Value);
      }

Output

Non-primitive data types

Now, we will create an Employee class. The class is given below.

public class Employee
   {
       public int Id { set; get; }
       public string Name { get; set; }
       public string Desgination { get; set; }
       public int Salary { get; set; }
   }

The code snippet given below creates a dictionary named employees, where the keys are integer and the value is an Employee type. Employee type is a custom create type.

Dictionary<int, Employee> employees = new Dictionary<int, Employee>(); Value assigns employee’s object. 

Employee employee1 = new Employee() { Id = 111, Name = "Popy", Desgination = "Software", Salary = 35000 };
            Employee employee2 = new Employee() { Id = 112, Name = "Popy", Desgination = "Software", Salary = 35000 };
            Employee employee3 = new Employee() { Id = 113, Name = "Mitila", Desgination = "Sr.Software", Salary = 35000 };

Add the values into employees of Dictionary. 

employees.Add(employee1.Id,employee1);
employees.Add(employee2.Id, employee2);
employees.Add(employee3.Id, employee3);

Read all the data. 

foreach (KeyValuePair<int, Employee> aemployee in employees)
           {
               Console.WriteLine("Name = {0}, Desgination = {1}, Salary = {2}",
               aemployee.Value.Name, aemployee.Value.Desgination, aemployee.Value.Salary);
           }

Output

The count number of the items of dictionary is given below.

int numberofRow = employees.Count;

Remove an item from dictionary.

employees.Remove(employee3.Id);

Clear dictionary items

employees.Clear();

Hope, this will be helpful.