In c#, Property is an extension of the class variable and it provides a mechanism to read, write or change the value of the class variable without affecting the external way of accessing it in our applications.
In c#, properties can contain one or two code blocks called accessors and those are called a get
accessor and set
accessor. By using get
and set
accessors, we can change the internal implementation of class variables and expose it without effecting the external way of accessing it based on our requirements.
Generally, in object-oriented programming languages like c# you need to define fields as private, and then use properties to access their values in a public way with get
and set
accessors.
Following is the syntax of defining a property with get
and set
accessor in c# programming language.
<access_modifier> <return_type> <property_name>
{
get
{
// return property value
}
set
{
// set a new value
}
}
If you observe the above syntax, we used an access modifier and return type to define a property along with get
and set
accessors to make required modifications to the class variables based on our requirements.
Here, the get
accessor code block will be executed whenever the property is read and the code block of set
accessor will be executed whenever the property is assigned to a new value.
In c#, the properties are categorized as three types, those are.
Type | Description |
---|---|
Read-Write | A property which contains a both get and set accessors, then we will call it as read-write property. |
Read-Only | A property which contains only get accessor, then we will call it as a read-only property. |
Write-Only | A property which contains only set accessor, then we will call it as write-only property. |
In c#, Properties won’t accept any parameters and we should not pass a property as a ref or out parameter in our application.
Following is the simple example of defining a private variable and a property in c# programming language.
class User
{
private string name;
public string Name
{
get { return name; }
set { name = value; }
}
}
If you observe the above example, we defined a property called “Name” and we used a get
accessor to return a property value and set
accessors to set a new value. Here, the value keyword in set
accessor is used to define a value that is being assigned by set
accessor.
In c#, the get
accessor needs to be used only to return the field value or to compute it and return it but we should not use it for changing the state of an object.
As discussed, we can extend the behavior of class variables using properties get
and set
accessors. Following is the example of extending the behavior of private variable in property using get
and set
accessors in c# programming language.
class User
{
private string name = "Suresh Dasari";
public string Name
{
get
{
return name.ToUpper();
}
set
{
if (value == "Suresh")
name = value;
}
}
}
If you observe the above example, we are extending the behavior of private variable name using a property called Name with get
and set
accessors by performing some validations like to make sure Name value equals to only “Suresh” using set
accessor and converting property text to uppercase with get accessor.
Here the field “name” is marked as private so if you want to make any changes to this field then we can do it only by calling the property (Name).
In c# properties, the get
accessor will be invoked while reading the value of a property and when we assign a new value to the property, then the set
accessor will be invoked by using an argument that provides the new value.
Following is the example of invoking get
and set
accessors of properties in c# programming language.
User u = new User();
u.Name = "Rohini"; // set accessor will invoke
Console.WriteLine(u.Name); // get accessor will invoke
In the above example, when we assign a new value to the property, then the set
accessor will be invoked and the get
accessor will be invoked when we try to read the value from property.
Following is the example of defining properties with get
and set
accessors to implement required validations without effecting the external way of using it in c# programming language.
using System;
namespace Tutlane
{
class User
{
private string location;
private string name = "Suresh Dasari";
public string Location
{
get { return location; }
set { location = value; }
}
public string Name
{
get
{
return name.ToUpper();
}
set
{
if (value == "Suresh")
name = value;
}
}
}
class Program
{
static void Main(string[] args)
{
User u = new User();
// set accessor will invoke
u.Name = "Rohini";
// set accessor will invoke
u.Location = "Hyderabad";
// get accessor will invoke
Console.WriteLine("Name: " + u.Name);
// get accessor will invoke
Console.WriteLine("Location: " + u.Location);
Console.WriteLine("\nPress Enter Key to Exit..");
Console.ReadLine();
}
}
}
If you observe above example, we are extending the behaviour of private variables (name, location) using properties (Name, Location) with get
and set
accessors by performing some validations like to make sure Name value is equals to only “Suresh” using set
accessor and converting property text to uppercase with get
accessor.
When you execute the above c# program, we will get the result as shown below.
If you observe the above example, our variable text converted to upper case and even after we set variable text as “Rohini”, it displayed text as “Suresh Dasari” because of the set
accessor validation fails in the property.
As discussed, if a property contains the only get
accessor, then we will call it as a read-only property. Following is the example of creating read-only properties in c# programming language.
using System;
namespace Tutlane
{
class User
{
private string name;
private string location;
public User(string a, string b)
{
name = a;
location = b;
}
public string Name
{
get
{
return name;
}
}
public string Location
{
get
{
return location;
}
}
}
class Program
{
static void Main(string[] args)
{
User u = new User("Suresh Dasari", "Hyderabad");
// compile error
// u.Name = "Rohini";
// get accessor will invoke
Console.WriteLine("Name: " + u.Name);
// get accessor will invoke
Console.WriteLine("Location: " + u.Location);
Console.WriteLine("\nPress Enter Key to Exit..");
Console.ReadLine();
}
}
}
If you observe above example, we created a properties using only get
accessor to make the properties are read-only based on our requirements.
In case, if we uncomment the commented code then we will get a compile error because our Name property doesn’t contain any set
accessor to set a new value. It’s a just read-only property.
When you execute the above c# program, you will get a result like as shown below.
This is how we can create read-only properties in c# applications based on our requirements.
As discussed, if a property contains the only set
accessor, then we will call it as write-only property. Following is the example of creating write-only properties in c# programming language.
using System;
namespace Tutlane
{
class User
{
private string name;
public string Name
{
set
{
name = value;
}
}
private string location;
public string Location
{
set
{
location = value;
}
}
public void GetUserDetails()
{
Console.WriteLine("Name: " + name);
Console.WriteLine("Location: " + location);
}
}
class Program
{
static void Main(string[] args)
{
User u = new User();
u.Name = "Suresh Dasari";
u.Location = "Hyderabad";
// compile error
//Console.WriteLine(u.Name);
u.GetUserDetails();
Console.WriteLine("\nPress Enter Key to Exit..");
Console.ReadLine();
}
}
}
If you observe above example, we created a properties using only set
accessor to make the properties are write-only based on our requirements.
In case, if we uncomment the commented code then we will get a compile error because our Name property doesn’t contain any get
accessor to return a value. It’s a just write-only property.
When you execute the above c# program, you will get a result like as shown below.
This is how we can create write-only properties in c# applications based on our requirements.
In c#, a property is called as an auto-implemented property when it contains accessors (get, set) without having any logic implementation.
Generally, the auto-implemented properties are useful whenever there is no logic implementation required in property accessors.
Following is the example of creating auto-implemented properties in c# programming language.
using System;
namespace Tutlane
{
class User
{
public string Name { get; set; }
public string Location { get; set; }
}
class Program
{
static void Main(string[] args)
{
User u = new User();
u.Name = "Suresh Dasari";
u.Location = "Hyderabad";
Console.WriteLine("Name: " + u.Name);
Console.WriteLine("Location: " + u.Location);
Console.WriteLine("\nPress Enter Key to Exit..");
Console.ReadLine();
}
}
}
If you observe above example, we created a properties with get
and set
accessors without having any logic implementation.
When you execute the above c# program, we will get a result like as shown below.
This is how we can create auto-implemented properties in c# applications based on our requirements.
The following are the important points which we need to remember about properties in c# programming language.
get
and set
accessors by hiding implementation details.get
accessor is used to return a property value and a set
accessor is used to assign a new value.set
accessor is used to define a value which is going to be assigned by the set
accessor.