What is the purpose of private member with public getter and setter? c#

Question

what is the different between writing the getter and setter directly like this:

public string Name {get; set;}

and like this:

private string _name;

public string Name
{
    get
    {
       return this._name;
    }
    set
    {
        this._name = value;
    }
}

I saw that in lots of codes. why they use a private member than a public getter and setter.

is it for performance or privacy or what is the point? thank you.

Answer 1

what is the different between writing the getter and setter directly like this

public string Name {get; set;}

They're essentially the same.

The code below you're basically creating the private field and providing both getters and setters for it, which of course does the intended idea. However, the language implementors decided they could make the life of a programmer easier by providing a shorter syntax where you can create a private field and at the same time provide a getter or setter or both.

private string _name;

public string Name
{
    get
    {
       return this._name;
    }
    set
    {
        this._name = value;
    }
}

So, in C# 3 they(language implementors) came up with the idea of making the syntax shorter by enabling a programmer to simultaneously create a private field and at the same time provide a getter or setter or both.

Behind the scenes, all that happens for the code below is the compiler creates a private field and also provides a getter and setter for it. So, basically, it's shorter more concise syntax to achieve the same task as the example above.

auto-implemented property

public string Name {get; set;}

Answer 2

There is none.

The thing is: auto-implemented properties weren't available until C# 3 (if you look at the documentation referenced: it goes back to VS 2008 which was released with C# 3), and not all code was written in the C# 3 era. Also, not all developers are aware of this feature. If I would stumble across this kind of code, I would rewrite it to use auto-implemented properties.

Answer 3

An property is just a short hand and will create at the background an public get method and a public set method and a private field to store the value.

Example Code

 // example property
 public string Name { get; set; }

// at run time it is the same as:
private string Name;

public string GetName(){
  return this.Name;
}

public string SetName(string name){
  this.Name = name;
}

See Image :

The sample class only has an property in code Name. If you use Reflection to get all the members off the Sample class you will see that at run time set_name() and get_name() methods are generated. These methods are not specified in in code.

Answer 4

Short answer, there isn't a difference. The compiler will convert the "auto" property to that style regardless, it's just saving you the writer a few keystrokes. It really only comes into play when you start working with DataBinding or having to do something else in the Set portion.

private string _name;

public string Name
{
    get
    {
       return this._name;
    }
    set
    {
        this._name = value;OnPropertyChange();
    }
}

In WPF/XAML/DataBinding, this would let anyone subscribed to this object know that a property with the name "Name" has changed and it should reflect so in the UI.

Answer 5

The first one is called an auto-implemented property. Second one is used when you want to add some custom code logic that validates the value in your setter.

Answer 6

You can control what happens in the getter & setters, whereas if the member was public, the variable could be modified directly.

private string _name;

public string Name
{
    get
    {
       return this._name + " likes chocolate";
    }
    set
    {
        this._name = value;
    }
}

Here, your private _name always stays the same, but anyone accessing Name will get _name + " likes chocolate".

In the setter, you could do some validation.