Demo code for re using Nationale nieuwsquiz data from: http://tools.ncrv.nl/nnqapi/doc/#get-questions. A database which contains popquizzes with pictures on dutch topics.

nnq.php

<?php
// Written by AJ SLAGHUIS in 2013

$limit = 10000; // lets get 'm all at 10.000
$page = 0;

/*
 * Retrieving Quiz Id's
 */
$uri = "http://tools.ncrv.nl/nnqapi/index.php/quizzes/$limit/$page";
$file = file_get_contents($uri);
$json = json_decode($file); //print_r($json);
//print("error $json->error \t " . "total $json->total \t "
// . "total_pages $json->total_pages \t " . "page $json->page \t "
// . "limit $json->limit \n");
echo "Records " . count($json->result) . "\n";
for ($i = 0; $i < count($json->result); $i += 1) {
    //    $quiz = $json->result[$i];
    //       print("id $quiz->id \t" . "widgetid $quiz->widget_id \t"
    //            ."name $quiz->name \t" . "date $quiz->date \t"
    //            ."published $quiz->published \t" );
    //     $quiz->question array is always empty, because ???
}

// let's just pick a random quiz
$n = rand(0, count($json->result));
echo "Random Pick Quiz " . $n . "\n";
$quiz = $json->result[$n];
print("id $quiz->id \t" . "widgetid $quiz->widget_id \t"
        . "name $quiz->name \t" . "date $quiz->date \t"
        . "published $quiz->published \t");

/*
 * Retrieving a Quiz by using an quiz ID
 */

$jsonq = json_decode(file_get_contents("http://tools.ncrv.nl/nnqapi/index.php/quiz/$quiz->id"));
//print_r($jsonq);
print( "error " . $jsonq->error . "\n");
echo "Records " . count($jsonq->result->questions) . "\n";

for ($i = 0; $i < count($jsonq->result->questions); $i += 1) {
    //    $question = $jsonq->result->questions[$i];
    //    print("id $question->id \t" . "quizid $question->quiz_id \t"
    //            . "title $question->title \n" . "text $question->text \t"
    //            . "type $question->type \n"
    //            . "answer_a $question->answer_a \t"
    //            . "answer_b $question->answer_b \t"
    //            . "answer_c $question->answer_c \t"
    //            . "answer_d $question->answer_d \n"
    //            . "correct_answer $question->correct_answer \t"
    //            . "seconds $question->seconds \t"
    //            . "points $question->points \n\n");
}

// let's just pick a random quiz
$n = rand(0, count($jsonq->result->questions));
echo "Random Pick Question" . $n . "\n";
$question = $jsonq->result->questions[$n];
print("id $question->id \t" . "quizid $question->quiz_id \t"
        . "title $question->title \n" . "text $question->text \t"
        . "type $question->type \n"
        . "answer_a $question->answer_a \t"
        . "answer_b $question->answer_b \t"
        . "answer_c $question->answer_c \t"
        . "answer_d $question->answer_d \n"
        . "correct_answer $question->correct_answer \t"
        . "seconds $question->seconds \t"
        . "points $question->points \n\n");

/*
 * Retrieving Questions
 * get contents of: http://tools.ncrv.nl/nnqapi/index.php/questions/:limit/:page
 * with for example: http://tools.ncrv.nl/nnqapi/index.php/questions/10000/0
 * Questions also list the field mediafile which contains content like:
 * http:\/\/www.nationalenieuwsquiz.nl\/data\/media\/c9a433f29e70246add40c70b23e557e5.jpg
 */

/*
 * Retrieving a Question by using an question ID
 * get contents of: http://tools.ncrv.nl/nnqapi/index.php/question/:id
 * with: http://tools.ncrv.nl/nnqapi/index.php/question/1223
 * Questions also list the field mediafile which contains content like:
 * http:\/\/www.nationalenieuwsquiz.nl\/data\/media\/c9a433f29e70246add40c70b23e557e5.jpg
 */


?>