Re: the same memory location can have different values

From:

"Bo Persson" <bop@gmb.dk>

Newsgroups:

comp.lang.c++

Date:

Tue, 9 Jun 2009 18:06:51 +0200

Message-ID:

<797fkaF1p4dhvU1@mid.individual.net>

Floare Augustin Theodor wrote:

On Jun 8, 11:54 pm, Floare Augustin Theodor
<floare.augustin.theo...@gmail.com> wrote:

On Jun 8, 10:12 pm, "Alf P. Steinbach" <al...@start.no> wrote:

Therefore, sizeof(int) is replaced with an integer number and
that number can be printed as an integer or as a float.

Schildt's first printf is incorrect, just Undefined Behavior.

I didn't know that
printf("%f", 2)
is not going to print 2.00000.
Actually, it prints 0.00000.

2 does not have the correct type (=> undefined behavior), but on my
machine sizeof(int) = sizeof(float) = 4 bytes.
So, printf will reinterpret the 32 bits of the integer as being
the 32 bits of a float?

Regards,
Teo

I am wrong again (that is why is hard to write a book :-) you need
to keep testing the code over and over again and read the manual
too).

Like others have said, you cannot rely on tests alone - because as
soon as you involve some undefined behavior, the test results are not
reliable.

You have to read the manual, or your textbook, FIRST.

Bo Persson