C# Automatic Properties

I'm a bit confused on the point of Automatic properties in C# e.g

public string Forename{ get; set; }

I get that you are saving code by not having to declare a private variable, but what's the point of a property when you are not using any get or set logic? Why not just use

public string Forename; 

I'm not sure what the difference between these 2 statements is, I always thought you used properties if you wanted additional get/set logic?

Properties can have code put into them without breaking contract, fields can't have code put into them without changing them to properties (and breaking the interface). Properties can be read only or write only, fields can't. Properties can be data bound, fields can't.

You can write

public string Forename{ get; private set; }

to get read-only properties... Still not nearly as versatile as real properties, but it's a compromise that for some works.

I'm not sure what the difference between these 2 statements is, I always thought you used properties if you wanted additional get/set logic?

In the first case, the compiler will automatically add a field for you, and wrap the property. It's basically the equivalent to doing:

private string forename;
public string Forename
{
    get
    { 
        return this.forename;
    }
    set
    {
        this.forename = value;
    }
}

There are many advantages to using properties over fields. Even if you don't need some of the specific reasons, such as databinding, this helps to future-proof your API.

The main problem is that, if you make a field, but in v2 of your application, need a property, you'll break the API. By using an automatic property up front, you have the potential to change your API at any time, with no worry about source or binary compatibility issues.

It is meant that you expect to add the logic later.

If you do so and have it as property from the beginning, you will not have to rebuild the dependent code. If you change it from a variable to a property, then you will have to.