1.效果图：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Math.random方法彩票随机数的生成</title>
</head>
<body>
<!-- 设置样式 -->
<input type="text" id="text">
<button id="btnGo">开始</button>
<button id="btnStop">获取随机数组</button> <script type="text/javascript"> //获取节点
var btnGo = document.getElementById("btnGo");
var btnStop = document.getElementById("btnStop");
var text = document.getElementById("text");
//定义生成最小到最大值的随机函数
function rand(min,max){
return parseInt(Math.random()*( max - min + 1) + min);
} function start(min,max,length){
//定义空数组
var arr = []; while(arr.length<length){
//生成一个随机数prem
var prem=rand(min,max);
//判断生成的随机数prem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(prem) == -1){ arr.push(prem);
}
}
//返回数组arr
return arr;
} var timer = 0;
//单击开始按钮生成随机数组
btnGo.onclick =function(){
//清除
clearInterval(timer);
timer = setInterval(function() {
text.value = start(1,33,7);
},50)
}
//单击停止按钮获取一组随机数
btnStop.onclick =function(){
clearInterval(timer);
} </script>
</body>
</html>
2.复杂版
<!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>