jquery - How to Learn JavaScript Correctly Quiz Issue -

-

i'm working through how learn javascript correctly. halfway through has create quiz application. i'm able display first question, clicking next button changes second question. problem when click button third time, screen clears , third question never appears.

i'm sure i'm missing easy. idea i'm going wrong?

app.js:

var allquestions = [     {question: "who prime minister of united kingdom?",      choices: ["david cameron", "gordon brown", "winston churchill", "tony blair"],      correctanswer:0},     {question: "who president of united states?",      choices: ["george bush", "barack obama", "hilary clinton"],      correctanswer:1},     {question: "what best state?",      choices: ["iowa", "wisconsin", "colorado", "north carolina"],      correctanswer:1}     ];  var score = 0; var = 0;   $(document).ready(function() {     $('#next').addclass('hidden');      nextquestion();  });  function nextquestion() {     var container = $('#container');      var questionname = allquestions[i].question     var answer = allquestions[i].correctanswer;     var choice = 0;      var question = "<div>" + questionname + "</div>";     container.append(question + "<br>");     var choices = allquestions[i].choices;     (var j=0;j<choices.length;j++) {         var choice = choices[j];         var radio = "<input type='radio' data-choice='" + j + "' value='" + choice + "' name='" + allquestions[i].question + "'>" + choices[j];         container.append(radio + "<br>");     }      $('input:radio').on('click',function() {         choice = $(this).data("choice");         $('#next').removeclass('hidden');      });      $('#next').on('click',function() {         $('#next').addclass('hidden');         if (choice === answer) {             alert("winner!");         }         if (i < allquestions.length) {             += 1;         }         container.empty();         nextquestion();      }); }

index.html:

<!doctype html> <html lang="en"> <head>   <meta charset="utf-8">   <meta http-equiv="x-ua-compatible" content="ie=edge,chrome=1">   <title>survey</title>   <link rel="stylesheet" href="assets/bootstrap.min.css">   <link rel="stylesheet" href="assets/bootstrap.responsive.min.css">   <link rel="stylesheet" href="assets/base.css">  </head> <body>    <!-- index.html -->   <div id="container">      <script src="js/lib/jquery.min.js"></script>   <script src="js/lib/underscore-min.js"></script>   <script src="js/lib/bootstrap.min.js"></script>   <script src="js/app.js"></script>   </div>   <input type='submit' value='next' id='next'> </body> </html>

remove following code withing function; you're binding events multiple times. @ time when click #next once may advance multiple time responds multiple binds.

$('input:radio').on('click',function() {     choice = $(this).data("choice");     $('#next').removeclass('hidden');  });  $('#next').on('click',function() {     $('#next').addclass('hidden');     if (choice === answer) {         alert("winner!");     }     if (i < allquestions.length) {         += 1;     }     container.empty();     nextquestion();  });

put code inside dom ready event modification shown:

$(function() {     $(document).on('change', 'input:radio', function() {         choice = $(this).data("choice");         $('#next').removeclass('hidden');      });      $('#next').on('click',function() {         $('#next').addclass('hidden');         if (choice === answer) {             alert("winner!");         }         if (i < allquestions.length) {             += 1;         }         container.empty();         nextquestion();      }); });

Comments

Post a Comment

Popular posts from this blog

php - render data via PDO::FETCH_FUNC vs loop -

-
i've been using 2 methods render data. the first one: function name($id,$name){ return '<div id="'.$id.'">'.$name.'</div>'; } echo implode($pdo->query("select id,name user")->fetchall(pdo::fetch_func,'name')); the second one: $users = $pdo->query("select id,name user")->fetchall(pdo::fetch_obj); foreach($users $user){ echo name($user->id,$user->name); } i don't understand how pdo::fetch_func works. tried figure out. however, not well-documented. could please explain fetch mode? , also, 1 performs better? thank you. both methods wrong , have learn how use templates , how separate business logic presentation logic. $users = $pdo->query("select id,name user")->fetchall(pdo::fetch_obj); tpl::assign('users', $users); is code business logic part. then in template <?php foreach $users $row): ?> <div id="<?=$...
Read more

c++ - OpenCV Error: Assertion failed <scn == 3 ::scn == 4> in unknown function, -

-
i read alot other solution still confused should mine... #include <opencv2/objdetect/objdetect.hpp> #include <opencv2/highgui/highgui.hpp> #include <opencv2/imgproc/imgproc.hpp> #include <iostream> #include <stdio.h> using namespace std; using namespace cv; int main(int argc, const char** argv) { //create cascade classifier object used face detection cascadeclassifier face_cascade; //use haarcascade_frontalface_alt.xml library face_cascade.load("haarcascade_frontalface_alt.xml"); //setup video capture device , link first capture device videocapture capturedevice; capturedevice.open(0); //setup image files used in capture process mat captureframe; mat grayscaleframe; //create window present results namedwindow("outputcapture", 1); //create loop capture , find faces while (true) { //capture new image frame capturedevice >> captureframe; ...
Read more

The canvas has been tainted by cross-origin data in chrome only -

-
uncaught securityerror: failed execute 'getimagedata' on 'canvasrenderingcontext2d': canvas has been tainted cross-origin data i getting above error in chrome. code(following) works fine in mozilla. have not corss domain issue. why above error in chrome? var wheel_canvas, wheel_context, can_w, can_h, wheel_grd; var large_radius = 160; var small_radius = 120; var wheel_canvas = document.getelementbyid('wheel_canvas'); var wheel_context = wheel_canvas.getcontext('2d'); var can_w = $(wheel_canvas).width(); var can_h = $(wheel_canvas).height(); var centerx = can_w / 2, centery = can_h / 2; var wheel_grd = null; test('#ff0000'); function test(hex) { $('#clrpicker').css({'left': 210, 'top': 210 }); inverted = hexbw(hex); $('#color_val_show').val(hex); current_color_hex_val_selected = hex; $('#color_val_show').css({'color':inverted,'background':hex}); fillgradient...
Read more