js实现随机抽选效果、随机抽选红色球效果

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>caipiao</title>
</head>
<body>
  <div id="wrap"></div>
  <button id="goBtn">go</button>
  <button id="stopBtn">stop</button>
  <script type="text/javascript">
  var wrap = document.getElementById("wrap");
  var goBtn = document.getElementById("goBtn");
  var stopBtn = document.getElementById("stopBtn");
  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;
  }
    //rndArray(最小范围值,最大范围值,个数)
  wrap.innerHTML = rndArray(1,33,7);
  var timer = 0;
  goBtn.onclick = function() {
    clearInterval(timer);
    timer = setInterval(function() {
      wrap.innerHTML = rndArray(1,33,7);
    },100)
    console.log(timer);
  }
  stopBtn.onclick = function() {
    clearInterval(timer);
  }
  </script>
</body>
</html>

随机抽选

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>caipiao</title>
  <style type="text/css">
    * {
      margin:0;
      padding: 0;
    }
    #wrap {
      width:621px;
      margin:0 auto;
      padding:50px 0;
      background-color:rgb(255, 242, 242);
    }
    #inner {
      width:490px;
      margin:0 auto;
      overflow: hidden;
    }
    #inner span {
      float: left;
      width:30px;
      height: 30px;
      border-radius: 15px;
      border:1px solid #d9d9d9;
      line-height: 30px;
      text-align: center;
      color:#333;
      background-color: #f8f8f8;
      margin:18px 6px;
    }
    #inner span.active {
      background-color: red;
      color:#fff;
    }
    #wrap p {
      text-align: center;
    }
    button {
      border:none;
      outline: none;
      width:120px;
      height: 40px;
      line-height: 40px;
      font-size: 20px;
      border-radius: 4px;
    }
    #selectBtn {
      background-color: red;
      color:#fff;
    }
  </style>
</head>
<body>
  <div id="wrap">
    <div id="inner">
      <span>01</span>
      <span>02</span>
      <span>03</span>
      <span>04</span>
      <span>05</span>
      <span>06</span>
      <span>07</span>
      <span>08</span>
      <span>09</span>
      <span>10</span>
      <span>11</span>
      <span>12</span>
      <span>13</span>
      <span>14</span>
      <span>15</span>
      <span>16</span>
      <span>17</span>
      <span>18</span>
      <span>19</span>
      <span>20</span>
      <span>21</span>
      <span>22</span>
      <span>23</span>
      <span>24</span>
      <span>25</span>
      <span>26</span>
      <span>27</span>
      <span>28</span>
      <span>29</span>
      <span>30</span>
      <span>31</span>
      <span>32</span>
      <span>33</span>
    </div>
    <p>
      <button id="selectBtn">机选红球</button>
      <button id="clearBtn">清空</button>
    </p>
  </div>
  <script type="text/javascript">
  var wrap = document.getElementById("wrap");
  var selectBtn = document.getElementById("selectBtn");
  var clearBtn = document.getElementById("clearBtn");
  var ballList = document.getElementById("wrap").getElementsByTagName("span");
  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;
  }
  selectBtn.onclick = function() {
    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";
    }
  }
  clearBtn.onclick = function() {
    for(var j = 0; j < ballList.length; j++) {
      ballList[j].className = "";
    }
  }
  </script>
</body>
</html>

要实现点击得到自动随机数还得在clearBtn.onclick前面添加个定时器

var timer = 0;
  selectBtn.onclick = function() {
    clearTimeout(timer);
    timer = setInterval(selectBall,100);
    setTimeout(function() {
      clearTimeout(timer);
    },3000)
    // clearTimeout(timer);
  }

这样就实现了动态图的功能了(*^__^*) 嘻嘻！

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