Question

How to convert a 1D coordinate into 2D indexes in PHP

Answer 1

$array2d = array(
        array( 1,  2,   3,  6,  0), 
        array(-5, -4,   0,  7,  9), 
        array( 1, 18, 100, 14,  6), 
        array( 9, 10,  27, 12, 13) );
        
$array1d = array(1, 2, 3, 6, 0, -5, -4, 0, 7, 9, 1, 18, 100, 14, 6, 9, 10, 27, 12, 13);
        
$cols = count($array2d[0]);
$index = 17;
    
$i = (int)($index / $cols);
$j = $index - ($i * $cols);
    
echo "i = " . $i . " j = " . $j . "\n";
    
echo $array1d[$index] . "\n";
echo $array2d[$i][$j];




/*
run:

i = 3 j = 2
27
27

*/

 

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