Topic: Sincpac code question

[jmaeding]

I was looking at the SincpacC3D code, and was not sure what this kind of statement does, from PlotStyleCommandParameter.cs:

public PlotStyleCommandParameter(string parameterPrefix) : this(parameterPrefix, true) { }

its clearly a constrcutor function, but what is the part after the : doing?
I can guess, but am sure I am wrong, its not an inheritance activity...
So am asking for raw C# help here, thx.

[It's Alive!]

It’s probably setting a default to another constructor in the class, i.e
PlotStyleCommandParameter(string parameterPrefix, bool flag)

[It's Alive!]

something like

Code: [Select]

  public class Foo
    {
        private string m_str; 
        private bool m_flag;

        public Foo(string str) : this(str, true){ }
        public Foo(string str, bool flag)
        {
            m_str = str;
            m_flag = flag;
        }
    }


[Glenn R]

Dan's right and it's sometimes called 'constructor chaining'.

[Glenn R]

In other words, you leverage other constructors, where it makes sense to do so, rather than supplying 'extra' constructors that overload and require an increasing number of parameters.

[Spike Wilbury]

That is done because in C# you can't have default arguments (am I right Glenn and Daniel? - if not I pay the next round of beers)

In C++ we can do something like this:

Code: [Select]

void MyFunction(double num, int index, CString str="My Default") { ... }


[Glenn R]

Spot on the money Luis...no defaulty argumentos for C#.

[jmaeding]

ah, makes sense now, the function below it has matching params, I had missed that.
Boy, what a useful thing, I can simplify several constructors I have done the hard way.

[Glenn R]

If that's new to you, I seriously suggest getting some books on C# and doing some reading...Andrew Troelsen's 'Pro C# blah blah' works from Apress spring to mind and are excellent.

[jmaeding]

I've got books that I know mention it, I had not noticed it for some reason.
Good advice though, I have a lot to learn.

[It's Alive!]

I have a lot to learn.

me too

[Glenn R]

me 3

[Spike Wilbury]

not me, I know to much already....        



and now seriously:



me cuatro.

[jmaeding]

come on Sincovec, "Me Sinco"...

[sinc]

come on Sincovec, "Me Sinco"...

Septo you beat me to it...  Oucho these puns hurt.   

[sinc]

Oops, skipped six.  It must've been taking a seis-ta.