Super strange problem with strings and reflection

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Prashant Deva - 26 Dec 2003 19:08 GMT

I am using reflection to initialize a string to a value.

After initializing, i see the value of the string in my debugger as-

type="breakpoint"

but strangely, when i put code like this

if(type=="breakpoint")
{
//do whatever
}

it FAILS!!!!

i used NUnit to perform a test and it says-

----------------------------------------------------------------------------
----------------
Debugger.Commands.InfoStructs.Test.BreakpointInfoTest.Test :
String lengths differ. Expected length=10, but was length=11.
Strings differ at index 10.

expected:<"breakpoint">
but was:<"breakpoint(a square box here, it cant be pasted in outlook)">
----------------------------------------------------------------------------
-----------------------

What exactly is happening?
when i do the type.Length in the debugger watch window it returns 10.

But strangely in the debugger if i manually do
type="breakpoint"
and then
type=="breakpoint"
it returns true?

i am using .net framework 1.0.

Any help will be fully appreciated.

PRASHANT

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Ken Pinard - 26 Dec 2003 23:28 GMT

Have you parsed the last character out of the string and then seen what the
ASC value is?

It would be helpful here.

If zero(0) then it is a string terminator and maybe it needs to be parsed
out.

HTHs
Ken

> I am using reflection to initialize a string to a value.
>
[quoted text clipped - 38 lines]
>
> PRASHANT

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Prashant Deva - 30 Dec 2003 08:40 GMT

Ok, i have found out that the problem is not due to reflection but due to
this-

if i make a char array which is even 1 more than the length of string to be
stored-
char[] a = new char[len+1];
and store chars in it till len and then make a string out of the array-
string s =a.ToString();
the returned string has "\0" in it.
So if the string you copied is "Hello" but if you compare it with "Hello"
it will fail-
if(s=="Hello") //this FAILS!
To make the test pass you have to do include the "\0" in the string, like
this-
if(s=="Hello\0")//this PASSES!

but strangely if you check for length it will return it to you without
considering the null.
int len = s.Length;// len is equal to 5. NOT 6

This seems to be a bug in .NET 1.0.

PRASHANT

> Have you parsed the last character out of the string and then seen what the
> ASC value is?
[quoted text clipped - 52 lines]
> >
> > PRASHANT

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Ken Pinard - 05 Jan 2004 02:39 GMT

Actually, this has been a feature of "C" since the beginning. If the length
was greater than 1 more than the length. It would have any previously
assigned character in the last character.

You need to do your own checking.

Ken

> Ok, i have found out that the problem is not due to reflection but due to
> this-
[quoted text clipped - 78 lines]
> > >
> > > PRASHANT

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Super strange problem with strings and reflection

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