do while until end of array

[Natural_Bugger]

how to use a Do While until of array?

    constexpr int n = 9;
    char grid[n][n];
   
    auto it=std::begin(grid);

    do {
        *(*it+1) = 'S'; // all fine
    } while (*it != end); // doesn't compile

[Bagavathi]

@Natural_Bugger said in do while until end of array:

end

What do you mean by 'end' ?

I hope, it should be std::end(grid).

[Natural_Bugger]

@Bagavathi

Thnx, but i tried that already.
well, i just want to loop of the length over the array.

constexpr int n = 9;
    char grid[n][n];
   
    auto it=std::begin(grid);

do {
            *(*it+1) = 'S';
        } while (*it != std::end(grid));

result in:

error: comparison between distinct pointer types ‘char*’ and ‘char (*)[9]’ lacks a cast [-fpermissive]
   71 |         } while (*it != std::end(grid));
      |                                      ^
error: comparison of distinct pointer types ('char *' and 'char *[9]')

[Natural_Bugger]

@Bagavathi

hehe

do {
            *(*it+1) = 'S';
        } while (it != std::end(grid));

i remove the "*" before "it" and it worked out.

[Natural_Bugger]

error, it does compile.
but the code doesn't work.
no indication of error, it just doesn't do anything and doesn't execute the code below the "Do While" loop.

[J.Hilk]

@Natural_Bugger
If only there was a function that would take any container and iterate over all its values 🤔
oh!
right:

constexpr int n = 9;
        char grid[n][n];

        for( auto c : grid){
            qDebug() << c;
        }

😉

[Natural_Bugger]

@J-Hilk

Thnx, i have multiple different "style" for loops in my source file going over the same array, all good.
i just wanted to try a "Do While", i don't need to access it values "perse", just stop at the end.

[Gerhard]

Hi,
this
do {
*(*it+1) = 'S';
} while (it != std::end(grid));
doesn't never end because the iterator is not incremented! (endless loop)