Question

I need to find matching items in an array based on min and max values in PHP. Short of an elaborate foreach,if,elseif,then clause, how can I efficiently get matching rows?

For example… Given array $arr (below), and the number 4, how can I return array rows 1,2, and 3?

$arr = array(
    0 => array( 'min' => 1,     'max' => 1,     'name' => 'alpha'),
    1 => array( 'min' => 1,     'max' => 9,     'name' => 'beta'),
    2 => array( 'min' => 1,     'max' => 19,    'name' => 'gamma'),
    3 => array( 'min' => 2,     'max' => 29,    'name' => 'delta'),
    4 => array( 'min' => 10,    'max' => 100,   'name' => 'epsilon'),
    5 => array( 'min' => 20,    'max' => 100,   'name' => 'zeta'),
    6 => array( 'min' => 30,    'max' => 100,   'name' => 'eta')
);

I’m hoping to turn this into a function. Something like this:

function findMatchingRows($n) {
    $arr = /*** see above ***/;
    /*** your answer! ***/
    return $matchingRows;
}

$n = 12;
print_r(findMatchingRows($n));

Expected result would be for above should be rows 2, 3, and 4. But I would expect it to work for any integer between 1 and 100.

Answer 1

$number = 4;
$result = array_filter($arr, function ($elem) use ($number) {
   return $elem['min'] <= $number && $number <= $elem['max'];
});