Filter rows of a 2d array using multiple mathematical conditions

Question

I need to retain rows in my multidimensional array where multiole conditions must be met.

$positions = [
    ['64', '64', 'home.png', 'www.sdsd.vf'],
    ['128', '640', 'icon-building64.png', 'www.sdsd232.vf']
];

for ($i = 0; $i < 700; $i += 64) {
    for($j = 0; $j < 1100; $j += 64) {
        $out = array_filter(
            $positions, 
            function($position) {
                  return ($position[0] == $j AND $position[1] == $i);
             });    
        $out = array_merge(array(), $out);
    }
}

I tried this but I get errors:

$out = array_filter(
    $positions,
    function($position, $i, $j) {
        return ($position[0] == $j AND $position[1] == $i);
    }
);

You are aware that both your for loops got no ending } (and one doesn't have {) — Shikiryu
– Shikiryu, Commented Feb 28, 2011 at 9:52

mickmackusa · Accepted Answer · 2023-10-29 07:36:50Z

1

You can consolidate all conditions inside of a solitary array_filter() call.

function filterPositions($value) {
    return $value[0] < 1100
           && $value[1] < 700
           && ($value[0] % 64 == 0)
           && ($value[1] % 64 == 0);
}
$out = array_filter($positions, 'filterPositions');

Or a more concise and modern version with arrow function syntax.

var_export(
    array_filter(
        $positions,
        fn($row) =>
            $row[0] < 1100
            && $row[1] < 700
            && ($row[0] % 64 == 0)
            && ($row[1] % 64 == 0)
    )
);

edited Oct 29, 2023 at 7:36

mickmackusa♦

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answered Feb 28, 2011 at 15:26

Geoffrey

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Comments

Shakti Singh · Accepted Answer · 2013-01-24 15:13:06Z

0

The best way to do this, is passing the $i and $j to your anonymous function

$out = array_filter($positions, function($position) use ($i, $j) {
                  return ($position[0] == $j AND $position[1] == $i);
    });

This way you will be avoiding hardcoding values in function.

answered Jan 24, 2013 at 15:13

Shakti Singh

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