Filter out unlucky numbers from a sequence.

unlucky-numbers.php

<?php

/**
 * Filter out unlucky numbers from a range
 */
$n = 50;

/**
 * Imperative approach
 */
function getLuckyFloorNumber($n) {
    $luckynumbers = [];
    foreach (range(1, $n) as $number) {
        if( strpos( strval($number), "4" ) === false
            && strpos( strval($number), "13" ) === false ) {
            array_push( $luckynumbers, $number );
        }
    }
    echo implode(", ", $luckynumbers);
}

/**
 * Declarative approach
 */
function getLuckyFloorNumber2($n) {
    echo implode(", ", array_filter(range(1, $n), function ($number){
        return strpos(strval($number), "4") === false && strpos(strval($number), "13") === false;
    }));
}