php从数组中随机选择若干不重复元素的方法

<?php
/*
 * $array = the array to be filtered
 * $total = the maximum number of items to return
 * $unique = whether or not to remove duplicates before getting a random list
 */
function unique_array($array, $total, $unique = true){
    $newArray = array();
    if((bool)$unique){
        $array = array_unique($array);
    }
    shuffle($array);
    $length = count($array);
    for($i = 0; $i < $total; $i++){
        if($i < $length){
            $newArray[] = $array[$i];
        }
    }
    return $newArray;
}
$phrases = array(Hello Sailor,Acid Test,Bear Garden,Botch A Job,Dark Horse,
    In The Red,Man Up,Pan Out,Quid Pro Quo,Rub It In,Turncoat,
    Yes Man,All Wet,Bag Lady,Bean Feast,Big Wig, Big Wig,Bear Garden
    ,All Wet,Quid Pro Quo,Rub It In);
print_r(unique_array($phrases, 1));
// Returns 1 result
print_r(unique_array($phrases, 5));
// Returns 5 unique results
print_r(unique_array($phrases, 5, false));
// Returns 5 results, but may have duplicates if
// there are duplicates in original array
print_r(unique_array($phrases, 100));
// Returns 100 unique results   
print_r(unique_array($phrases, 100, false));
// Returns 100 results, but may have duplicates if
// there are duplicates in original array