<div class="frame">  <div class="row">  <div class="col-xs-8 col-sm-8 col-md-8 col-lg-8 danmu-box-frame">   <div class="danmu-box">   </div>  </div>  <div class="col-xs-4 col-sm-4 col-md-4 col-lg-4 danmu-table-frame">   <table class="table .table-condensed danmu-table">   <thead>    <tr>    <th>     彈幕內容    </th>    <th>     彈幕時間    </th>    </tr>   </thead>   <tbody>   </tbody>   </table>  </div>  </div>  <div class="danmu-form">  <form class="form-inline">   <input type="text" class="form-control" placeholder="開始吐槽！">   <button type="button" class="btn btn-primary shoot">   發射彈幕！   </button>   <button type="button" class="btn btn-danger clear">   清空彈幕   </button>  </form>  </div> </div> <hr> <footer>  Designed By  <a  target="_blank">  Alen Hu  </a> </footer> 

$(document).ready(function() {  $(".shoot").on("click", startDanmu);  $("form").keypress(function(event) {  if (event.keyCode === 13) {   event.preventDefault();   startDanmu();  }  });  $(".clear").on("click", clearDanmu); });  //get random number in certain range function RandomNum(Min, Max) {  var Range = Max - Min;  var Rand = Math.random();  var num = Min + Math.round(Rand * Range);  return num; }  //time number add 0 before if <10 function plusZero(x) {  if (x < 10) {  x = "0" + x;  } else {  x = x;  }  return x; }  //start danmu function startDanmu() {   var message = $("input");  var messageVal = message.val();  var danmuMessage = "<span class='danmu-message'>" + messageVal + "</span>";   //get random color HEX  //u can also save the colors u want by array  var color = RandomNum(100000, 999999);   //get random danmu speed  var speed = RandomNum(10000, 20000);   //get random position Y  //danmu box height is 450, we set the danmu position Y max 400 in case it blocks the subtitle  var positionY = RandomNum(50, 400);   if (messageVal.length > 0) {  //insert danmu message into danmu box  $(".danmu-box").prepend(danmuMessage);   //have to use first() cuz we prepend the message, u can try what's gonna happen if no first()  //set it's style  $(".danmu-message").first().css({   "right": "0",   "top": positionY,   "color": "#" + color  });   //set it's animation  //from right 0 to left 0  //hide it after move  $(".danmu-message").first().animate({   left: '0px',  },  speed,  function() {   $(this).fadeOut();  });  //get danmu time  var time = new Date();  var month = time.getMonth() + 1;  var day = time.getDay();  var hour = time.getHours();  var minute = time.getMinutes();  var danmuTime = plusZero(month) + "-" + plusZero(day) + " " + plusZero(hour) + ":" + plusZero(minute);   //insert danmu message to table  if (messageVal.length > 6) {   messageVal = messageVal.substring(0, 6) + "...";  }  var messageToTable = "<tr><td>" + messageVal + "</td><td>" + danmuTime + "</td></tr>";  $(".danmu-table > tbody").prepend(messageToTable);   } else {}   //empty the input  message.val(""); }  //clear danmu box function clearDanmu() {  $(".danmu-box").html(""); }