Checking if an integer has increased C++

Question

so not too tough I just want to understand if the following is the most efficient/fast way of checking this;

if (misses++)
    run_code();

(Basically if misses increased, run some code, useful for logging missed angles etc.)

P.S will this code run every time misses increases? Thanks :)

EDIT

This does not check if it increased, anybody got any ideas?

This does not mean "if `misses` increased". It means "if `misses` is not `0` and then increment `misses`". — nwp, Nov 04 '17 at 12:22
It will be executed each time `missed` will not be equals to zero before incrementing it. — Jean-Baptiste Yunès, Nov 04 '17 at 12:22
It isn't efficient because it doesn't to the thing you want it to do. As for speed, that is irrelevant if it doesn't work. — juanchopanza, Nov 04 '17 at 12:22
Alright, thanks very much still learning, how can I check if it increased? @nwp — user8885290, Nov 04 '17 at 12:24
You'll need to keep track of its last value and then check if the value has increased since then. Or instead of ever incrementing misses, just call `run_code` if you want to call it whenever the value increases — Nick is tired, Nov 04 '17 at 12:25
and `if (misses)` means `misses` didnt not increase? Interesting language that you are making up ;). Suggested reading: https://stackoverflow.com/questions/388242/the-definitive-c-book-guide-and-list — 463035818_is_not_an_ai, Nov 04 '17 at 12:25
@BrunoCorrêaZimmermann That expression might or might not evaluate to `false` implicitly. The OP's logic is flawed to begin with. — Ron, Nov 04 '17 at 12:32
The best place to perform your action is the location where you increment `misses`. — Thomas Matthews, Nov 04 '17 at 16:50

score 1 · Answer 1 · answered Nov 04 '17 at 12:36

1

try like this:

int b=misses
misses++;
if(misses>b)
{
   run_code();
   b=misses;
}

answered Nov 04 '17 at 12:36

Sofi Ullah Saikat

622
4
20

This if doesn't do anything, the compiler will just remove it. – tkausl Nov 04 '17 at 12:38

score 1 · Answer 2 · answered Nov 04 '17 at 12:38

To determine whether a value has increased you have to make a note of the original value, so that you can compare:

void f(int& arg); // might change arg

int main() {
    int misses = 0;
    int old_misses;
    for (int i = 0; i < 10; ++i) {
        old_misses = misses;
        f(misses);
        if (misses != old_misses)
            run_code();
    }
    return 0;
}

Checking if an integer has increased C++

2 Answers2