如何不重複迭代在PHP

Question

我想打印custom_question不重複，它custom_question_answer在PHP中使用循環如下

Answer 1

可能有助於給你的分貝 鏈接，並獲得更清晰關於的想法。

<?php 
$arr = $arr_history = array("1stQuestion?","2ndQuestion?","3rdQuestion?","4thQuestion?"); 

for ($i = 0; $i < count($arr); $i++) 
{ 
    if (empty($arr_history)){ $arr_history = $arr; } 
    $key = array_rand($arr_history, 1); 
    $selected = $arr_history[$key]; 
    unset($arr_history[$key]); 
    echo $selected . PHP_EOL; 
} 

?>