Pull out random number of questions like 04 out of 10 - php

Question

I have function previously made which get me a set of questions array each time shuffled in a new set of order each time when i take a quiz with shuffle() function
Original array (Q1,Q2,Q3,Q4,Q5,Q6)
1st time it gives me (Q2,Q4,Q1,Q3,Q6,Q5)
2nd time it gives me (Q3,Q4,Q2,Q6,Q1,Q5) and so on.
everytime a new set of questions.
This is the function code working for only for shuffle
/**
* Update user questions.
*
* #param $quiz_id
* #param $course_id
* #param $user_id
*/
public function update_user_questions( $quiz_id, $course_id, $user_id ) {
global $wpdb;
$item = null;
switch ( current_action() ) {
case 'pmi-course/user/quiz-redone':
$item = $wpdb->get_row(
$wpdb->prepare( "
SELECT * FROM {$wpdb->prefix}pmicourse_user_items
WHERE item_id = %d
AND user_id = %d
AND ref_id = %d
ORDER BY user_item_id DESC
", $quiz_id, $user_id, $course_id )
);
break;
case 'pmi-course/user/quiz-started':
break;
}
if ( ! $item ) {
return;
}
if ( ! $item->status == 'started' ) {
return;
}
$random_quiz = get_user_meta( $user_id, 'random_quiz', true );
$quiz = LP_Quiz::get_quiz( $quiz_id );
if ( $quiz && $questions = $quiz->get_questions() ) {
$questions = array_keys( $questions );
shuffle( $questions );
$question_id = reset( $questions );
// set user current question
$user = pmi_course_get_current_user();
$user_course = $user->get_course_data( $course_id );
$item_quiz = $user_course->get_item($quiz_id);
$item_quiz->set_meta( '_current_question', $question_id );
$item_quiz->update_meta();
pmi_course_update_user_item_meta( $item->user_item_id, 'current_question', $question_id );
if ( empty( $random_quiz ) ) {
$random_quiz = array( $quiz_id => $questions );
} else {
$random_quiz[ $quiz_id ] = $questions;
}
update_user_meta( $user_id, 'random_quiz', $random_quiz );
}
}
/**
* Random quiz questions.
*
* #param $quiz_questions
* #param $quiz_id
*
* #return array
*/
public function random_questions( $quiz_questions, $quiz_id ) {
if ( get_post_meta( $quiz_id, '_lp_random_mode', true ) == 'yes' ) {
// get user meta random quiz
$random_quiz = get_user_meta( get_current_user_id(), 'random_quiz', true );
if ( is_admin() || empty( $random_quiz ) || empty( $random_quiz[ $quiz_id ] ) ) {
return $quiz_questions;
}
$questions = array();
if ( array_key_exists( $quiz_id, $random_quiz ) && sizeof( $random_quiz[ $quiz_id ] ) == sizeof( $quiz_questions ) ) {
foreach ( $random_quiz[ $quiz_id ] as $question_id ) {
if ( $question_id ) {
$questions[ $question_id ] = $question_id;
}
}
} else {
$question_ids = array_keys( $quiz_questions );
shuffle( $question_ids );
$random_quiz[ $quiz_id ] = $question_ids;
$questions = array();
foreach ( $question_ids as $id ) {
$questions[ $id ] = $quiz_questions[ $id ];
}
}
return $questions;
}
return $quiz_questions;
}
This is what i tried to pull out specific number of questions randomly like "4" questions out of "6" questions from a set but it gives the random result one time and not again like shuffle() i know array_rand() gives different value each time but why not in my case. may be i am doing something wrong . I have put down both the case either can anyone identify me what i am doing wrong or the solution could be extended to more better. Any help would be appreciated.
Original array (Q1,Q2,Q3,Q4,Q5,Q6)
First time (Q1,Q4,Q5,Q6)
Second time (Q1,Q4,Q5,Q6)
Third time (Q1,Q4,Q5,Q6) ---i want different sets for each time
What i tried to achieve this
///for first function
if ( $quiz && $questions = $quiz->get_questions() ) {
$questions = array_rand( $questions , 4);
$question_id = reset( $questions );
///for second function
if ( array_key_exists( $quiz_id, $random_quiz ) && sizeof( $random_quiz[ $quiz_id ] ) < sizeof( $quiz_questions ) ) {
foreach ( $random_quiz[ $quiz_id ] as $question_id ) {
if ( $question_id ) {
$questions[ $question_id ] = $question_id;
}
}
} else {
question_ids = array_rand( $quiz_questions , 4);
$random_quiz[ $quiz_id ] = $question_ids;
questions = array();
foreach ( $question_ids as $id ) {
$questions[ $id ] = $quiz_questions[ $id ];
}
}

Answer 1

Simple function to grab a set of random elements from an array:
$questions = array("Question 1","Question 2","Question 3","Question 4","Question 5","Question 6","Question 7","Question 8","Question 9","Question 10");
function shuffle_questions($questions, $num_questions){
$random_questions = [];
for($i = 0; $i < $num_questions){
$random_num = rand(0, 9);
$random_questions[] = $questions[$random_num];
}
return $random_questions;
}
If you only want it to return unique questions (Probably what you're looking for)
function shuffle_questions($questions, $num_questions){
$questions_temp = $questions;
$random_questions = [];
for ($i = 0; $i++; $i < $num_questions){
$key = array_rand($questions_temp, 1);
$random_questions[] = $questions_temp[$key];
$unset($questions_temp[$key]);
}
return $random_questions;
}