this post was submitted on 09 May 2024
458 points (92.4% liked)
Programmer Humor
32718 readers
378 users here now
Post funny things about programming here! (Or just rant about your favourite programming language.)
Rules:
- Posts must be relevant to programming, programmers, or computer science.
- No NSFW content.
- Jokes must be in good taste. No hate speech, bigotry, etc.
founded 5 years ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
I didn't know why, but *++p bugs me
Perhaps *(p += 1) will be to your liking?
Much better... but can we make it
*((void*)(p = p + 1))
?How about some JavaScript
p+=[]**[]
?Why are you casting to
void*
? How is the compiler supposed to know the size of the data you are dereferencing?This would probably cause a compiler error....
But assuming it doesn't the context is
p_ch =
the bits above... the code declaring p_ch isn't shown but I'm guessing that the value here is actuality a pointer to a pointer so nothing illegal would be happening.Lastly... C++ is really lacking in guarantees so you can assign a char to the first byte of an integer - C++ doesn't generally care what you do unless you go out of bounds.
The reason I'm casting to void* is just pure comedy.
++p
will increase the value and return the new valuep++
will increase the value and return the old valueI think
p = p + 1
is the same asp++
and not as++p
. No?In C an assignment is an expression where the value is the new value of what was being assigned to.
In
a = b = 1
, both a and b will be 1.is the same as
, so ++p.
What I meant was:
In the screenshot it said
x = *(++p)
and iirc that is not the same as sayingx = *(p++)
orx = *(p += 1)
As in my example using ++p will return the new value after increment and p++ or p+=1 will return the value before the increment happens, and then increment the variable.
Or at least that is how I remember it working based on other languages.
I'm not sure what the * does, but I'm assuming it might be a pointer reference? I've never really learned how to code in c or c++ specifically. Though in other languages ( like PHP which is based on C ) there is a distinct difference between
++p
and (p++
orp+= 1
)The last two behave the same. Though it has been years since I did a lot of coding. Which is why I asked.
I'll install the latest PHP runtime tonight and give it a try xD
(p += 1) resolves to the value of p after the incrementation, as does ( p = p + 1).
Yes.
p++
==p+= 1
==p = p + 1
are all the same if you use it in an assignment.++p
is different if you use it in an assignment. If it's in its own line it won't make much difference.That's the point I was trying to make.
No.
++p returns incremented p.
p += 1 returns incremented p.
p = p + 1 returns incremented p.
p++ returns p before it is incremented.
Right. So i had them the other way around. :D
Thanks for clarifying.
welcome to C
That
*++
operator from C is indeed confusing.Reminds me of the goes-to operator:
-->
that you can use as:That's not a real operator. You've put a space in "i--" and removed the space in "-- >". The statement is "while i-- is greater than zero". Inventing an unnecessary "goes to" operator just confuses beginners and adds something else to think about while debugging.
And yes I have seen beginners try to use <-- and --<. Just stop it.
The sheer number of people that do not expect a joke on this community... (Really, if you are trying to learn how to program pay attention to the one without the
Humor
on the name, not here.)Well, I guess nobody expects.
Where do you think we are?
It's very likely plain old C
Not if you've done a lot of pointer math
I thought it was just incrementing the address and dereferencing it, but I don't write C or C++. What is being overloaded there?