Array Lookup [Was: Why is "Hello World" const char* ?]

[Hans]

Hello,

Thanks for all your response on my question about signed/unsigned chars.

The problem is this: I want to use the char array for a ArrayLookup, so
I need to convert char to unsigned int.

But this doesn't work!

If I try this:

#include <stdio.h>
int main() {
char c = -1; // 129 unsigned and -1 signed right?
// convert it to a value between 0 - 255 for array Lookup
unsigned int arrayIndex = (unsigned int) c;
if (arrayIndex < 0)
printf("ArrayIn dex still negative after conversion to unsigned int
%d\n",arrayInde x);
else
printf("Unsigne d representation is OK for ArrayIndex=%d\n ",arrayInde x);
}

The output is: "ArrayIndex still negative after conversion to unsigned
int -1"

How is this possible?

I would expect a output 129.

Thanks!

Hans

[Keith Thompson]

"TTroy" <ti*****@gmail. com> writes:
[...]

I don't think Mike meant the OP was truly lying for the purpose of
confusing c.l.c readers. He probably meant it as if he was suprised,
kind of like if someone says something unbelievable you might respond:
"No way, you're lying."

He did further go on to help the OP, so lighten up Keith. If you're
going to be such a hard a*s about every post on c.l.c. that is even a
little OT, incorrect or improper, then lead by example.
Read Mike's reaponse (which you probably hadn't seen when you posted
yours).
In the thread titled: "Do you like my strlcpy strlcat etc?" you join in
with other posters to mock the use of symabolic constants by the OP.
The OP didn't deserve that and everyone who responded just made fun of
him/her. You took part in a session where people kept making worse
versions of the original preprocessor defines. Not everyone has been
roaming c.l.c and programming in C for ages, so lighten up "a little"
or apply the same strict rules you enforce on yourself.

Yes, quite frankly, the OP did deserve to be mocked. He's been told
many times before, over several years, that his macros serve only to
make his code more difficult to read. He doesn't seem to care whether
he's actually communicating, which makes many of us wonder why he
wastes his time (and ours) by posting here. Perhaps I should have
just ignored it, but in this case I chose not to.

--
Keith Thompson (The_Other_Keit h) ks***@mib.org <http://www.ghoti.net/~kst>
San Diego Supercomputer Center <*> <http://users.sdsc.edu/~kst>
We must do something. This is something. Therefore, we must do this.

[CBFalconer]

TTroy wrote:

.... snip ...
In the thread titled: "Do you like my strlcpy strlcat etc?" you
join in with other posters to mock the use of symabolic constants
by the OP. The OP didn't deserve that and everyone who responded
just made fun of him/her. You took part in a session where people
kept making worse versions of the original preprocessor defines.
Not everyone has been roaming c.l.c and programming in C for ages,
so lighten up "a little" or apply the same strict rules you
enforce on yourself.

Yes he did deserve it. This is far from the first time he has been
told about it. The best use for trolls is as butts for jokes.

--
"If you want to post a followup via groups.google.c om, don't use
the broken "Reply" link at the bottom of the article. Click on
"show options" at the top of the article, then click on the
"Reply" at the bottom of the article headers." - Keith Thompson

[RoSsIaCrIiLoIA]

On Sat, 05 Feb 2005 23:35:27 GMT, CBFalconer <cb********@yah oo.com>
wrote:

TTroy wrote:

... snip ...

In the thread titled: "Do you like my strlcpy strlcat etc?" you
join in with other posters to mock the use of symabolic constants
by the OP. The OP didn't deserve that and everyone who responded
just made fun of him/her. You took part in a session where people
kept making worse versions of the original preprocessor defines.
Not everyone has been roaming c.l.c and programming in C for ages,
so lighten up "a little" or apply the same strict rules you
enforce on yourself.

Yes he did deserve it. This is far from the first time he has been
told about it. The best use for trolls is as butts for jokes.

I had thought on str[l]cpy str[l]cat
there is no need of strcpy, strcat they are easily emulate
with some loop (so strcpy strcat are errors)
For me your str[l]cpy has at last one error
if p is a pointer to char and sizeof(array pointed from p)=sz
if the array of chars poited from p have no 0 in the first sz-1
positions => str[l]cpy has to end it with a 0 in the sz-1 position.

I think strlcpy strlcat are too errors
I think there is only the need
sprintf for fast and accurate programming (that can emulate strcpy and
strcat)
and something like
snprintf(char* buffer, size_t size, char* fmt, ...); (that can emulate
strlcpy strlcat)
for everyday functions

the same for malloc:
one malloc for fast and accurate programming and a malloc2 that can
find the errors in memory for write out of bouds etc for everyday
functions

Then if you like a buggy language ...

[RoSsIaCrIiLoIA]

On Sat, 05 Feb 2005 22:28:10 GMT, Keith Thompson <ks***@mib.or g>
wrote:

"TTroy" <ti*****@gmail. com> writes:
[...]

I don't think Mike meant the OP was truly lying for the purpose of
confusing c.l.c readers. He probably meant it as if he was suprised,
kind of like if someone says something unbelievable you might respond:
"No way, you're lying."

He did further go on to help the OP, so lighten up Keith. If you're
going to be such a hard a*s about every post on c.l.c. that is even a
little OT, incorrect or improper, then lead by example.
Read Mike's reaponse (which you probably hadn't seen when you posted
yours).

In the thread titled: "Do you like my strlcpy strlcat etc?" you join in
with other posters to mock the use of symabolic constants by the OP.
The OP didn't deserve that and everyone who responded just made fun of
him/her. You took part in a session where people kept making worse
versions of the original preprocessor defines. Not everyone has been
roaming c.l.c and programming in C for ages, so lighten up "a little"
or apply the same strict rules you enforce on yourself.

Yes, quite frankly, the OP did deserve to be mocked. He's been told
many times before, over several years, that his macros serve only to
make his code more difficult to read. He doesn't seem to care whether
he's actually communicating, which makes many of us wonder why he
wastes his time (and ours) by posting here.

If you lost your time reading my message kill file my messages
but I think these macro are Right and ok because read these macro is
more easy for me.
Perhaps I should have
just ignored it, but in this case I chose not to.