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Implementing lottery random number generation based on javascript (upgraded version)_javascript skills

WBOYOriginal: 2016-05-16 15:20:321153browse

The example in this article explains how to use JavaScript to obtain the detailed code for random arrays in lottery tickets. It is shared with everyone for your reference. The specific content is as follows

Rendering:

Specific code:

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Math.random方法彩票随机数的生成-升级版</title>
  <style type="text/css">
   *{
     margin: 0;
     padding: 0;
   }
   .wrap{
     width: 600px;
     height: 300px;
     background-color: #f8e2e2;
     margin: 0 auto;
   }
   .list{
     width: 440px;
     /*border: 1px solid red;*/
     margin: 0px auto;
   }
   .list li{
      list-style: none;
      width: 30px;
      height: 30px;
      display: inline-block;
      border: 1px solid #fff;
      border-radius: 30px;
      line-height: 30px;
      text-align: center;
      margin: 15px auto 15px;
      /*background-color: #f8f8f8;*/
      /*background-color: rgba(255,255,255,1);*/
   }
   .wrap p{
     text-align: center;
   }
   .wrap p button{
     text-align: center;
     width: 100px;
   }
   #setBtn{
     background-color: red;
     color: #fff;
     border: none;
   }
   .active{
     background-color: red;
     color: #fff;
   }
  </style>
</head>
<body>
    <div class="wrap" id="wrap">
       <ul class="list">
         <li>01</li>
         <li>02</li>
         <li>03</li>
         <li>04</li>
         <li>05</li>
         <li>06</li>
         <li>07</li>
         <li>08</li>
         <li>09</li>
         <li>10</li>
         <li>11</li>
         <li>12</li>
         <li>13</li>
         <li>14</li>
         <li>15</li>
         <li>16</li>
         <li>17</li>
         <li>18</li>
         <li>19</li>
         <li>20</li>
         <li>21</li>
         <li>22</li>
         <li>23</li>
         <li>24</li>
         <li>25</li>
         <li>26</li>
         <li>27</li>
         <li>28</li>
         <li>29</li>
         <li>30</li>
         <li>31</li>
         <li>32</li>
         <li>33</li>
       </ul>
       <p>
         <button id="setBtn">随机红球</button>
        <button id="clearBtn">清空</button>
       </p>
    </div>
    <script type="text/javascript">
       var ballList = document.getElementById("wrap").getElementsByTagName("li");
       var setBtn =document.getElementById("setBtn");
       var clearBtn =document.getElementById("clearBtn");
       //定义随机数组
       function rnd(min, max) {
       return parseInt(Math.random()*(max - min + 1) + min);
     }
     function rndArray(min, max, length) {
    //先定义一个空数组
    var arr = [];
    //生成一个长度为7的数组
    while(arr.length < length) {
      //生成一个随机数
      var rand = rnd(min, max);
      //判断生成的随机数rand是否在数组arr里,果然不在，就将这个随机数插入到数组里，如果在，执行下一次循环
      if(arr.indexOf(rand) == -1) {
        arr.push(rand);
      }
    }
    arr.sort(function(a, b){return a - b;})
    return arr;
  }

  function selectBall() {
    for(var j = 0; j < ballList.length; j++) {
      ballList[j].className = "";  
    }
    var arr = rndArray(1,33,7);
    // console.log(arr);
    for(var i = 0; i < arr.length; i++) {
      ballList[arr[i]-1].className = "active";
    }
  }
  var timer = 0;
  setBtn.onclick = function() {
    clearTimeout(timer);
    timer = setInterval(selectBall,100);
    setTimeout(function() {  
      clearTimeout(timer);
    },3000)
    // clearTimeout(timer);
  }

  clearBtn.onclick = function() {
    clearTimeout(timer);
    for(var j = 0; j < ballList.length; j++) {
      ballList[j].className = "";  
    }
  }
    </script>
</body>
</html>

The above is the detailed content of this article. I hope it will be helpful to everyone in learning javascript programming.

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