始终使用this-keyword作为前缀（自动）属性是一种好习惯吗？

Question

Ever since I found out about auto properties, I try to use them everywhere. Before there would always be a private member for every property I had that I would use inside the class. Now this is replaced by the auto property. I use the property inside my class in ways I normally would use a normal member field. The problem is that the property starts with a capitol, which makes it look a bit weird imho when using it in this manner. I didn't mind that properties start with a capitol before because they would always be behind a "dot". Now I have found myself prefixing all the properties I use internally with this. , to sooth my feeling.

My dilemma is that before I was always a bit against prefixing all usage of internal members with this. , unless "necessary" (like in a setter or constructor). So I am kind of looking for a second opinion on this. Is there a standard good way to do this? Should I just stop complaining (I have the tendency to be a "ant humper" (Dutch expression))?

Before:

class Foo
{
    private Bar bar;
    public Bar Bar { get { return bar; } }

    public Foo(Bar bar)
    {
        this.bar = bar;
    }

    public void DoStuff()
    {
        if(bar != null)
        {
            bar.DoMethod();
        }
    }
}

After:

class Foo
{
    public Bar Bar {get; private set;}

    public Foo(Bar bar)
    {
        this.Bar = bar;
        // or
        Bar = bar;
    }

    public void DoStuff()
    {
        if(this.Bar != null)
        {
            this.Bar.DoMethod();
        }
        // or
        if(Bar != null)
        {
            Bar.DoMethod();
        }
    }
}

Update

It seems that opinions vary, although more people are in favor of prefixing with this. . Before the auto properties I was always pretty much against prefixing with this. instead of in constructors and in setters (as I mentioned before). But now I just don't know anymore.

Additional note: The fact that it is also common to name the property the same as the class ( public Bar Bar { get; private set; } ) also makes me tend towards prefixing. Every time I type Bar.DoMethod() , I feel like it looks like a static method. Even though VS would color Bar if it was a static method and you cannot have a static and instance method with the same signature. When it is colored it is clear that it is a static method, but when it is not colored it is not 100% clear that it is not a static method. You could for example just be missing a using statement, but also just because I am not used to having to link the not being colored to whether it's a static call or not. Before I'd instantly see it by the capitalization of the first letter in case of a member or by the "dot" in case of a property (Eg the "dot" after foo in (Foo)foo.Bar.DoMethod() ).

(Difficult to choose an "Accepted answer" at the moment)

Answer 1

Yes, there is a "standard way to do this": the capital letter and the this-prefix are considered good coding practice. If you use some tool to test your code for coding guidelines like ReSharper or Microsoft's own StyleCop , it will warn you if not using the this-reference, or if you don't start your properties with a capital.

Your properties are publicly visible. Any public property, field or method should start with a capital.

Any property, field or method that you call inside your own class that is part of that class should be prefixed with the this-reference for ease-of-reading.

Update : of course, opinions vary. I like hitting this. and then, after the dot, seeing only the members, instead of seeing all keywords when just hitting ctrl-space without any prefix. This helps me. But, in the end ( quote from here ):

Whatever your opinion, the important thing is that all people closely collaborating on a project use the same formatting standards, irrespective of what those standards are.

More references:
Microsoft on using a capital letter in almost any name and in properties specifically.
More guidelines here .

Answer 2

I strongly recommend to use ' this. ' where possible. Framework Design Guidelines recommends this practice. It lets you know the scope from readability point of view and helps you avoid silly mistakes which compiler may report at compile time.

Answer 3

And I strongly recommend never using this as it only ever reduces clarity. If you actually find yourself in an instance where you need this to avoid collisions I would recommend renaming one of the fields/properties/variables.

The only place I find it acceptable is if it's part of a publicly exposed API where renaming would cause a breaking change.

Answer 4

In the first example, the bar parameter lexically shadows bar field from the instance. So you have to use this for disambiguation.

In the 2nd example you have no such ambiguity, and hence does not need a disambiguation (ie this ). You can however still prefix it, if that is your cup of tea. :)