random(non- repeating) file generator on click of button in php - php

Question

i want to display 5 php files content randomly but non repeating when clicked a button [NEXT] using php/javascript (that works in php desktop as well).
the code i used did displayed random web page on page load but i did came across repeated web page
this is the code i used for index.php file:
<?php
$RandomList = array();
$RandomList[] = "/review/review-a1.php";
$RandomList[] = "/review/review-a2.php";
$RandomList[] = "/review/review-a3.php";
$RandomList[] = "/review/review-a4.php";
readfile($_SERVER['DOCUMENT_ROOT'].$RandomList[rand(0,count($RandomList)-1)]);
?>
please suggest how to get non repeated files .

Answer 1

Just save paths you already used in the session:
//Read visited paths from session or create a new list.
//?? works only in PHP7+. Use isset()?: instead of ?? for previous versions
$visitedPaths = $_SESSION['visitedPaths'] ?? [];
//Your list, just slightly changed syntax. Same thing
$randomList = [
"/review/review-a1.php",
"/review/review-a2.php",
"/review/review-a3.php",
"/review/review-a4.php"
];
//Remove all paths that were already visited from the randomList
$randomList = array_diff($randomList, $visitedPaths);
//You need to check now if there are paths left
if (!empty($randomList)) {
//The user did not load all files, so we can show him the next one
//Use array_rand() rather than $array[rand(0, count($array) -1)]
$randomPath = $randomList[array_rand($randomList)];
readfile($_SERVER['DOCUMENT_ROOT'] . $randomPath);
//Now we need to save, that the user loaded this file
$visitedPaths[] = $randomPath;
//And we need to save the new list in the session
$_SESSION['visitedPaths'] = $visitedPaths;
} else {
//TODO: Add some logic in case all paths have been visited
}