C# object initialization options

Question

Doesn't object initialization outside of a constructor break encapsulation ?

Given:

class MyClass 
{  
    public string _aString;  
}

Shouldn't the _aString member be private and instantiated via a call to the constructor (constructor omitted here):

 MyClass test = new MyClass("test");

Instead of the alternate method of object initialization:

MyClass test = new MyClass { _aString = "Test" };

Answer 1

"Doesn't object initialization outside of a constructor break encapsulation ?"

Well, no. As you rightly pointed out you can only initialize properties that are already accessible in your current scope. (public, internal etc)

This kind of Intialization is really just some syntactic sugar around construction of a class and assigning values to properties, It is very useful for Anonymous classes and Linq select clauses.

Answer 2

It is usually considered bad practice to expose public fields... it may be acceptable in some cases, for instance if the field is marked as readonly (which means it must be set in the constructor). Instead, you should make this field private and expose it through a property, which may or may not be readonly, depending on its purpose :

class MyClass
{
    private string _aString;
    public string AString
    {
        get { return _aString; }
        // uncomment to make the property writable
        //set { _aString = value; }
    }
}