原生JS实现随机点名项目的实例代码

核心思想

•随机产生规定范围内的整数，然后再产生相同范围内的整数，两者相同时，则暂停。

所用知识

•math.random() * num: 产生从0到num的随机数
•math.floor(): 向下取整
•简单的dom操作等

技术扩展

•扩展人数
•添加停止键等

效果

代码如下

•html:

 <div class="container">
  <section class="demo">
   <ul>
    <li></li>
    <li></li>
    <li></li>
   </ul>
  </section>
  <section class="students"><ul></ul></section>
  <section class="buttonlist">
   <ul>
    <li><button type="button">随机选一个</button></li>
    <li><button type="button">随机选两个</button></li>
    <li><button type="button">随机选三个</button></li>
   </ul>
  </section>
 </div>

•css:

 <style type="text/css">
  * {
   margin: 0;
   padding: 0;
  }
  ul {
   list-style: none;
  }
  body {
   width: 100%;
   height: 100%;
   background: url("images/bg.jpg") no-repeat;
   background-size: cover;
  }
  button {
   border: none;
   background-color: transparent;
   color: #fff;
   font-size: 20px;
  }
  .container {
   width: 1200px;
   height: 700px;
   margin: 10px auto;
  }
  .container .demo, .container .buttonlist {
   width: inherit;
   height: 25%;
  }
  .container .students {
   width: inherit;
   height: 50%;
  }
  .container .students li {
   margin-right: 50px;
   margin-bottom: 30px;
   text-align: center;
   border-radius: 10px;
   font-size: 20px;
   font-weight: bold;
  }
  .container .students li:nth-child(5n) {
   margin-right: 0;
  }
  .container .buttonlist li button {
   float: left;
   width: 200px;
   height: 60px;
   background-color: #4caf5085;
   margin-right: 150px;
   text-align: center;
   line-height: 60px;
   border-radius: 10px;
   margin-top: 50px;
   font-weight: bold;
  }
  .container .buttonlist li button:hover {
   background-color: #4caf50;
  }
  .container .buttonlist li:nth-child(1) {
   margin-left: 150px;
  }
  .container .demo li {
   width: 200px;
   height: 150px;
   background-color: #4caf5085;
   float: left;
   margin-right: 150px;
   border-radius: 50%;
   margin-top: 10px;
   line-height: 150px;
   font-weight: bold;
   color: #fff;
   font-size: 60px;
   text-align: center;
  }
  .container .demo li:first-child {
   margin-left: 150px;
  }
 </style>

•javascript:

<script type="text/javascript">
  var stuarray = ["小方", "小田", "小明", "小红", "小吕", "小于", "小美", "小绿", "李华", "小李", "小胡",
   "小夏", "小徐", "小小", "小吴", "小陈", "小狗", "小许", "小熊", "小新"];
  var stulist = document.queryselector(".students").queryselector("ul");
  var buttonlist = document.queryselectorall("button");
  var demolist = document.queryselector(".demo").queryselectorall("li");
  

  for (var i = 0; i < stuarray.length; i++) {
   var li = document.createelement("li");
   stulist.appendchild(li);
   li.innerhtml = stuarray[i];
   li.style.cssfloat = "left";
   li.style.width = 200 + "px";
   li.style.height = 60 + "px";
   li.style.backgroundcolor = "#4caf5085";
   li.style.color = "#fff";
   li.style.lineheight = 60 + "px";
  }

  var stuarraylist = stulist.queryselectorall("li");

  function chooseone () {
   for (var i = 0; i < stuarraylist.length; i++) {
    stuarraylist[i].style.background = "#4caf5085";
   }
   for (var i = 0; i < demolist.length; i++) {
    demolist[i].innerhtml = "";
   }
   var interid = setinterval(function () {
    var x = math.floor(math.random() * stuarray.length);
    stuarraylist[x].style.backgroundcolor = "green";
    demolist[1].innerhtml = stuarraylist[x].innerhtml;
    var timeid = settimeout(function () {
     stuarraylist[x].style.backgroundcolor = "#4caf5085";
    }, 100);
    var y = math.floor(math.random() * stuarray.length);
    if (y == x) {
     cleartimeout(timeid);
     clearinterval(interid);
     stuarraylist[y].style.backgroundcolor = "green";
    }
   }, 100);
  }

  function choosetwo () {
   for (var i = 0; i < stuarraylist.length; i++) {
    stuarraylist[i].style.background = "#4caf5085";
   }
   for (var i = 0; i < demolist.length; i++) {
    demolist[i].innerhtml = "";
   }
   var interid = setinterval(function () {
    do {
     var x1 = math.floor(math.random() * stuarray.length);
     var x2 = math.floor(math.random() * stuarray.length);
    } while (x1 == x2);
    stuarraylist[x1].style.backgroundcolor = "green";
    stuarraylist[x2].style.backgroundcolor = "green";
    demolist[0].innerhtml = stuarraylist[x1].innerhtml;
    demolist[2].innerhtml = stuarraylist[x2].innerhtml;
    var timeid = settimeout(function () {
     stuarraylist[x1].style.backgroundcolor = "#4caf5085";
     stuarraylist[x2].style.backgroundcolor = "#4caf5085";
    }, 100);
    var y1 = math.floor(math.random() * stuarray.length);
    var y2 = math.floor(math.random() * stuarray.length);
    if ((y1 == x1 && y2 == x2) || (y1 == x2 && y2 == x1)) {
     cleartimeout(timeid);
     clearinterval(interid);
     stuarraylist[x1].style.backgroundcolor = "green";
     stuarraylist[x2].style.backgroundcolor = "green";
    }
   }, 100);
  }

  function choosethree () {
   for (var i = 0; i < stuarraylist.length; i++) {
    stuarraylist[i].style.background = "#4caf5085";
   }
   for (var i = 0; i < demolist.length; i++) {
    demolist[i].innerhtml = "";
   }
   var interid = setinterval(function () {
    do {
     var x1 = math.floor(math.random() * stuarray.length);
     var x2 = math.floor(math.random() * stuarray.length);
     var x3 = math.floor(math.random() * stuarray.length);
    } while (x1 == x2 || x2 == x3 || x1 == x3);
    stuarraylist[x1].style.backgroundcolor = "green";
    stuarraylist[x2].style.backgroundcolor = "green";
    stuarraylist[x3].style.backgroundcolor = "green";
    demolist[0].innerhtml = stuarraylist[x1].innerhtml;
    demolist[1].innerhtml = stuarraylist[x2].innerhtml;
    demolist[2].innerhtml = stuarraylist[x3].innerhtml;
    var timeid = settimeout(function () {
     stuarraylist[x1].style.backgroundcolor = "#4caf5085";
     stuarraylist[x2].style.backgroundcolor = "#4caf5085";
     stuarraylist[x3].style.backgroundcolor = "#4caf5085";
    }, 100);
    var y1 = math.floor(math.random() * stuarray.length);
    var y2 = math.floor(math.random() * stuarray.length);
    var y3 = math.floor(math.random() * stuarray.length);
    if ((x1 == y1 && x2 == y2) || (x1 == y2 && x2 == y1)) {
     cleartimeout(timeid);
     clearinterval(interid);
     stuarraylist[x1].style.backgroundcolor = "green";
     stuarraylist[x2].style.backgroundcolor = "green";
     stuarraylist[x3].style.backgroundcolor = "green";
    }
   }, 100);
  }
  buttonlist[0].addeventlistener("click", function () {chooseone()}, false);
  buttonlist[1].addeventlistener("click", function () {choosetwo()}, false);
  buttonlist[2].addeventlistener("click", function () {choosethree()}, false);

总结

以上所述是小编给大家介绍的原生js实现随机点名项目的实例代码，希望对大家有所帮助