logo
down
shadow

Modifying elements of Haskell 2D array


Modifying elements of Haskell 2D array

By : user2955780
Date : November 22 2020, 10:48 AM
seems to work fine No, the ++ operator does not do that. It simply concatenates two lists together. With [[1]] ++ [[2]], you could say x = [1] and y = [2], then you have [x] ++ [y], which is clearly [x, y], or [[1], [2]] through direct substitution.
As for solving your current problem, I would recommend writing a function that can replace an element at an index in a simple list, as in
code :
replace :: Int -> a -> [a] -> [a]
replace i x xs = ???
change_elem row col x xs =
    let row_to_replace_in = xs !! row
        modified_row = replace col x row_to_replace_in
    in replace row modified_row xs


Share : facebook icon twitter icon
PHP modifying array elements by reference

PHP modifying array elements by reference


By : Rose
Date : March 29 2020, 07:55 AM
Any of those help i think you're trying to redefine an existing php function which is array_walk. And especially in your case, you'll need array_walk_recursive.
Here's a rewritten (simplified ?) version of your code.
code :
    public function index( )
    {
        $arr = array( 
            array('a' => 'aap', 'n' => 'noot', 'm' => 'mies'), 
            array('a' => 'ding', 'b' => 'flof', 'c' => 'bips'), 
            array( 'd' => 'do', 'e' => 're', 'c' => 'mi') 
        );

        $func = array( $this, '_user_func' );

        var_dump($arr); // BEFORE WALK
        array_walk_recursive($arr, $func);
        var_dump($arr); // AFTER WALK
    }

    /**
     *  Does something to a row from an array (notice the reference)
     */
    private function _user_func( &$rowValue, $rowIndex )
    {
            $rowValue = 'replaced';
    }
Modifying an array through a ref to one of its elements - Will it work?

Modifying an array through a ref to one of its elements - Will it work?


By : Andrie Lim
Date : March 29 2020, 07:55 AM
I wish this helpful for you It is safe to modify value types in an array through a method which uses a ref to the element in the array, as shown below? If so, what kinds of value types can be modified this way? Is it limited to simple value types or will struct also work? , Yes, this works fine.
Your sample code will print:
code :
1
Modifying elements of an array through a function

Modifying elements of an array through a function


By : Holland Fuller
Date : March 29 2020, 07:55 AM
Any of those help What you are trying to do will not work since the signature of a function taking int a[] as an argument does not contain the necessary length information needed to write a for-each loop (i.e. to instantiate the begin() and end() templates needed to use the for-each syntax). GCC's warning says this fairly clearly:
code :
Error:(14, 19) cannot build range expression with array function parameter 'a' since 
parameter with array type 'int *[]' is treated as pointer type 'int **'
template <size_t N>
void incArray(int (&a)[N]) {
    for(auto& x : a) {
        ++x;
    }
}

int main(int argc, const char * argv[])
{
    int array[] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9};

    for (auto x : array) {
        cout << x << " ";
    }
    cout << endl;

    incArray(array);

    for (auto x : array) {
        cout << x << " ";
    }
    cout << endl;

    return 0;
}
Copying and modifying array elements

Copying and modifying array elements


By : KaTO
Date : March 29 2020, 07:55 AM
around this issue The for loop in which you copy the values from oldscores to newscores is never run in the case of SCORES_SIZE == 1, since SCORES_SIZE - 1 == 0, and 0 < 0 is false immediately.
Move the newScores[SCORES_SIZE - 1] = oldScores[0]; line outside the for loop:
code :
for (i = 0; i < SCORES_SIZE - 1; i++) {
  newScores[i] = oldScores[i + 1]; 
}
newScores[SCORES_SIZE - 1] = oldScores[0];
Haskell: Modifying value at specific index of array

Haskell: Modifying value at specific index of array


By : user2814017
Date : March 29 2020, 07:55 AM
it fixes the issue You don't actually need to modify the array. Just make your function create a new array that has the change you want, like this:
code :
modifyArray :: Array Int Char -> Int -> Array Int Char
modifyArray arr i =
    if i > 0 then
        if i `mod` 102 == 1 then
            arr // [(i, ' ')]
        else modifyArray arr (i-1)
    else arr   
shadow
Privacy Policy - Terms - Contact Us © ourworld-yourmove.org