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I think here[^] you will learn when to create new threads.
SkyWalker
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Exactly what i couldn't find. Many thanks.
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Converting value type into reference is Boxing, and vice-varsa is UnBoxing.
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ReenaSharma wrote: Converting value type into reference is Boxing
Almost. 
You don't "convert" anything - boxing is the process of placing a primitive type in an object so that the primitive type can be used as an object. See this Wikipedia[^] link.
/ravi
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let's say we have these 2 classes. Class B inherits from class A
class A
{
}
class B : A
{
}
in the following code
A obja;
B objb = new B();
obja = objb; // boxing
B objc = (B)obja; // unboxing
We can say,
Boxing is assigning an object of the child type to an object of the parent type (higher in the inheritance hierarchy)
Unboxing is (casting) assigning an object of the parent type to an object of the child type.
see also
Eslam Afifi
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Eslam Afifi wrote: Boxing is assigning an object of the child type to an object of the parent type
No, that's not correct. There is no boxing going on there.
Despite everything, the person most likely to be fooling you next is yourself.
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Maybe I'm wrong, but this is how I understand it, and I'll be grateful if you clarify this point to me, please.
B objc = (B)obja;
Isn't that unboxing?
Eslam Afifi
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No, that's not unboxing.
Unboxing is when you extract the value from a value type that is stored as an object. What you are doing is merely changing the type of a reference.
Despite everything, the person most likely to be fooling you next is yourself.
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Thank you. Now I get it. But I have one question. Does this reference conversion consume much time as unboxing?
Eslam Afifi
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Eslam Afifi wrote: Does this reference conversion consume much time as unboxing?
No. Reference conversion doesn't create a new object, it only verifies that the object can be used as the desired type and then copies the reference. If you convert from one known class to another, the verification can be done by the compiler, so the only thing that is done at runtime is copying the reference.
Despite everything, the person most likely to be fooling you next is yourself.
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Ok. Thank you so much.
Eslam Afifi
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Have a look at this[^] entry in wikipedia.
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Eslam Afifi wrote: class A
{
}
class B : A
{
}
in the following code
A obja;
B objb = new B();
obja = objb; // boxing
B objc = (B)obja; // unboxing
Wrong!
Boxing does not happen with instances of classes.
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Boxing is copying a value type (C# struct) to a reference object in the heap.
Unboxing is copying a boxed object in the heap back to the stack.
Not just primitive value types:
struct S : ISomeInterface
{
...
}
// boxing
S s1 = new S() ;
object x = s1 ; // S instance is created on the stack, then copied to the heap.
ISomeInterface is = s1 ; // This is also boxing
...
S s = (S)x ; // This is unboxing, for unboxing you must use the cast syntax.
Value types are not always placed on the stack, they are inline into it's container. They might be already on the heap, for instance if they are array elements.
S[] a = ...
a[i] = (S)x ;
Boxed value is copied from the heap to the stack and then copied into a[i].
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Hi all!
I have added a combobox control in the datagrid. I want to restrict user to select the value which is already selected in the datagrid.....
Thanx for ur help in advance!!!!
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i made a skydome for my model using xna and it displays very well. but for some computers, it doesn't show. is it something wrong with my coding or the hardware? 
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Sounds that way...
Christian Graus - Microsoft MVP - C++
"also I don't think "TranslateOneToTwoBillion OneHundredAndFortySevenMillion FourHundredAndEightyThreeThousand SixHundredAndFortySeven()" is a very good choice for a function name" - SpacixOne ( offering help to someone who really needed it ) ( spaces added for the benefit of people running at < 1280x1024 )
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I need to know the license in which a software could have at the end
In some applications you see many expressions about that ,would any descibe me or
give me a link to that?
Thnaks
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Pooya Musavi wrote: give me a link to that?
Clickety[^]
/ravi
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I am very new to this. I am trying to remove duplicates from a string.
string str="a badb ce b";
I want the return to "a bdce"
I think we will need two for loops
for (int i=0; i<str.lenght; i++)<br="" mode="hold">{
for (int j=i+1;j<str.length;j++)>
{
}
}
Is this approach correct? I haven't been able to proceed. please help.
Tina_K
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This should put you on the right path:
create the string to be returned;
foreach (character in the original string) {
if (the character doesn't exist in the string to be returned) {
add it to the string to be returned;
}
}/ravi
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