c# initializing

Question

is it necessary to initialize an auto property?

public string thingy { get; set; }

the reason I ask is because I have just come across a bunch of code where it was used where, the default value of null being an acceptable value.

the compiler does not complain.

as a general point, why does the compiler enforce initializations if it will default numbers to zero and object references to null anyway?

The compiler enforces initializations on local variables - they never get default values. Member variables on the other hand will get default values. — Dan Byström, Aug 03 '12 at 08:18

score 5 · Answer 1 · answered Aug 03 '12 at 08:05

autopropeties initialize by default(T) if you want initialize by special value you can use backing field:

private string _thingy = "value";
public string Thingy
{
    get { return _thingy; }
    set { _thingy = value; }
}

or set value in constructor

public class MyClass
{
    public string Thingy{get;set;}
    public MyClass()
    {
        Thingy = "value";
    }
}

or set in any method

score 3 · Accepted Answer · answered Aug 03 '12 at 08:17

3

The compiler enforces initializations for local variables, not for fields or properties. C# requires that local variables be definitely assigned because use of unassigned local variables is a common source of program bugs. That's not because the unassigned variable might contain garbage -- the CLR guarantees that it will not -- but because the programmer has probably made a mistake in the code.

The compiler doesn't treat fields or properties the same way because it's impossible to do the necessary flow analysis across multiple methods that could be called in any order.

answered Aug 03 '12 at 08:17

phoog

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Also worth reading is the answer from Eric Lippert here: http://stackoverflow.com/questions/8931226/are-c-sharp-uninitalized-variables-dangerous/8933935#8933935 – NoviceProgrammer Aug 03 '12 at 08:43
@NoviceProgrammer thanks for posting that link. Almost everything I know about the C# compiler comes from Eric's blog or his answers on stackoverflow. – phoog Aug 03 '12 at 08:53

c# initializing

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