Question

Possible Duplicate:
When do you use the “this” keyword?

Hello,
I understand that the This keyword is used to refer to an instance of the class, however, suppose I have a class called Life, which defines two fields, the person (their name) and their partner(their name):

class Life
{
    //Fields
    private string _person;
    private string _partner;

    //Properties
    public string Person
    {
        get { return _person; }
        set { _person = value; }
    }

    public string Partner
    {
        get { return _partner; }
        set { _partner = value; }
    }

    //Constructor 1
    public Life()
    {
        _person = "Dave";
        _partner = "Sarah";

        MessageBox.Show("Life Constructor Called");
    }

    //Constructor 2
    public Life()
    {
        this._person = "Dave";
        this._partner = "Sarah";

        MessageBox.Show("Life Constructor Called");
    }
}

Is there a difference between constructor 1 and constructor 2!?
Or is it just better coding practice to use the “This” keyword?

Regards

Answer 1

The constructors are the same. The reason I would prefer the second is that it will allow you to remove the underscores from your private variable names and retain the context (improving understandability). I make it a practice to always use this when referring to instance variables and properties.

I no longer use the this keyword in this way after moving to a different company with different standards. I’ve gotten used to it and now rarely use it at all when referring to instance members. I do still recommend using properties (obviously).

My version of your class:

class Life
{
    //Fields
    private string person;
    private string partner;

    //Properties
    public string Person
    {
        get { return this.person; }
        set { this.person = value; }
    }

    public string Partner
    {
        get { return this.partner; }
        set { this.partner = value; }
    }


    public Life()
    {
        this.person = "Dave";
        this.partner = "Sarah";

        MessageBox.Show("Life Constructor Called");
    }
}

or, even better, but not as clear about the use of this with fields.

class Life
{

    //Properties
    public string Person { get; set; }
    public string Partner { get; set; }

    public Life()
    {
        this.Person = "Dave";
        this.Partner = "Sarah";

        MessageBox.Show("Life Constructor Called");
    }
}