October 14. 2009 11:57

Cred ca "someVariable" este de tipul bool? (nullable bool).

Petre Bogdan Florin

October 14. 2009 11:59

It should be of type bool? (System.Nullable<bool>).
If you use nullable types, you should check them first if has value (.HasValue)

I am waiting you next riddle

Thank you,
George

George

October 14. 2009 15:58

"bool?"

Programatorul lui peste

October 14. 2009 16:39

My guess was a nullable bool ( I mean - what else could it be ? )

But I wasn't sure of the reason until I tested it. if takes a bool parameter , not a Nullable<bool>

sirrocco

October 14. 2009 17:38

bool? )

mtz

October 14. 2009 17:48

Two possibilities:

1. bool?

2. A class that overloads == operator, without overloading true and false operators , and without defining an implicit conversion to bool.

Ex:

using System;
class Program
{
static void Main(string[] args)
{
Program p = null;
if (p == false)
Console.WriteLine("P e null");
p = new Program();
if (p == true)
Console.WriteLine("P nu mai e null");

}

public static bool operator ==(Program p, bool value)
{
return (p != null) == value;
}

public static bool operator !=(Program p, bool value)
{
return (p == null) == value;
}
}

Pop Catalin

October 14. 2009 18:26

Simpatic quiz-ul, mi-a placut!

Raspunsul este: someVariable este un nullable bool. Compararea someVariable == true trece pentru ca COMPARI un nullable bool cu un bool, pe cand in if(someVariable) compilatorul se asteapta ca someVariable sa fie bool iar operatorul de casting T?->T de pe Nullable<T> este EXPLICIT si nu IMPLICIT, din care cauza iti da eroare la compilare ca vrea sa faci cast explicit la bool in if.

Sunt si eu pasionat de quiz-uri C#, daca-ti face placere poti vizita categoria asta de pe blogul meu: blogs.ugidotnet.org/.../272.aspx?Show=All (sunt in italiana dar textul in general cred ca se intelege)

Adrian Florea

October 15. 2009 09:41

Ma bucur pentru toate raspunsurile primite
Intr-adevar in situatia reala din care am descoperit aceasta mica ghicitoare aveam un System.Nullable<bool> aka "bool?".

Ma bucur si ca v-a placut ghicitoarea

Andrei Rinea

October 16. 2009 10:08

Si mie mi-a placut !

Andrei Ignat