@Tyoda@lemm.ee
link
fedilink
29
edit-2
6M

Perhaps *(p += 1) will be to your liking?

Much better… but can we make it *((void*)(p = p + 1))?

How about some JavaScript p+=[]**[]?

@Faresh@lemmy.ml
link
fedilink
English
36M

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.

@fluckx@lemmy.world
link
fedilink
11
edit-2
6M
p = 1

x = ++p
// x = 2
// p = 2
p = 1
x  = p++
// x = 1
// p = 2

++p will increase the value and return the new value

p++ will increase the value and return the old value

I think p = p + 1 is the same as p++ and not as ++p. No?

(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.

@Tyoda@lemm.ee
link
fedilink
10
edit-2
6M

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.

a = *(p = p + 1)

is the same as

p += 1
a = *p

, so ++p.

What I meant was:

In the screenshot it said x = *(++p) and iirc that is not the same as saying x = *(p++) or x = *(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++ or p+= 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

Create a post

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.
  • 1 user online
  • 149 users / day
  • 308 users / week
  • 697 users / month
  • 2.84K users / 6 months
  • 1 subscriber
  • 1.57K Posts
  • 34.8K Comments
  • Modlog