JavaScript实现大乐透号码生成的实例分析_懂视

JavaScript实现大乐透号码生成的实例分析

2020-11-27 20:11:34 责编:小采

这个“大乐透号码生成器”纯前端开发，涉及HTML、JS、CSS。为了简单起见，把所有代码写到了一个html文件中，这样的好处就是可以直接用浏览器打开这个文件，当然实际工作中最好把他们放在不同的文件。整个区域放在一个大的p标签中，表现为一个矩形区域，并通过JS控制显示的位置；设置一个下拉列表，可以选择生成1-5组随机号码，当点击按钮后，就能生成相应组数的号码；号码区域分两部分，上面部分是随机生成的无序的号码，下面部分是对这些无序号码进行排序后的号码，生成组数受上面下拉列表控制。这个工具的核心是生成随机号码和对随机号码进行排序，这两步都是通过JS代码实现的。下面介绍一些重要的JS代码。

生成随机号码：大乐透分前区号码和后区号码，前区号码是从01-35中无重复地取5个号码，后区号码是从01-12中无重复地取2个号码，组成一组7位的号码。这里定义了两个数组：arr35存放前区的01-35号码，arr12存放后区的01-12号码。通过“temp = Math.floor(Math.random()*arr35.length)”方法从0-arr35.length取一个随机数作为索引，通过arr35[temp]即可获取数组中该索引位置的值，也就是随机号码，然后通过获取id动态添加到排序前的span中。取完以后通过“arr35.splice(temp,1);”即可删除数组中该随机数，同时使数组长度减一。循环5次即可从01-35中无重复地取5个随机号码，后面两位同样如此。

var arr35 = ["01","02","03","04","05","06","07","08","09","10","11","12","13","14","15","16","17", 
"18","19","20","21","22","23","24","25","26","27","28","29","30","31","32","33","34","35"];
var arr12 = ["01","02","03","04","05","06","07","08","09","10","11","12"];
var span = "";
var temp = "";
for(var i=1;i<6;i++){
 span = "span" + x + i;
 temp = Math.floor(Math.random()*arr35.length);//随机取一个数
 document.getElementById(span).innerText = arr35[temp];
 document.getElementById(span).style.backgroundColor = "red";
 arr35.splice(temp,1);//删除该位置的值}

随机号码排序：这里用到了插入排序算法，只是对每组号码的前五位进行排序，数据量很小，排序完之后通过获取id动态添加到排序后的span中。

//插入排序
function bubbleSort(array){ 
var len = array.length; 
for (var i = 0; i < len; i++) { 
for (var j = i; j > 0 && array[j]<array[j-1]; j--) { 
var swap = array[j]; //第二个for循环使元素比较并移动到合适位置
 array[j] = array[j-1];
 array[j-1] = swap;
 }
 } return array;
}

其余的JS以及HTML、CSS技术不再详细介绍。

完整代码：

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>大乐透号码生成器</title>
<style type="text/css">
#table{
width:800px; 
height:500px;
margin:10px;
border:2px 
solid 
#000000;
box-shadow: 10px 10px 5px;border-radius:50px;}
.buttonStyle{height:40px;margin:20px;font-size:20px;background-color:#95ED;color:white;border-radius:10px;}
.oneStyle{margin-left:200px;margin-top:10px;font-family:sans-serif;font-size:20px;}
span{border-radius: 50%;color: #FFFFFF;padding:3px;font-size:13px;}
</style>
</head>
<body>
 <p id="table">
 <p>
 <h1 style="text-align:center">大乐透号码生成器</h1>
 </p>
 <p class="oneStyle">
 生成组数：<select id="zushu" style="width:150px;height:30px;margin:10px;" onchange="select()">
 <option value="1">生成 1 组号码</option>
 <option value="2">生成 2 组号码</option>
 <option value="3">生成 3 组号码</option>
 <option value="4">生成 4 组号码</option>
 <option value="5">生成 5 组号码</option>
 </select>
 </p>
 <p class="oneStyle">
 随机号码1：<span id="span11"></span> <span id="span12"></span> <span id="span13"></span> 
 <span id="span14"></span> <span id="span15"></span>
    <span id="span16"></span> <span id="span17"></span><br>
 随机号码2：<span id="span21"></span> <span id="span22"></span> <span id="span23"></span> 
 <span id="span24"></span> <span id="span25"></span>
    <span id="span26"></span> <span id="span27"></span><br>
 随机号码3：<span id="span31"></span> <span id="span32"></span> <span id="span33"></span> 
 <span id="span34"></span> <span id="span35"></span>
    <span id="span36"></span> <span id="span37"></span><br>
 随机号码4：<span id="span41"></span> <span id="span42"></span> <span id="span43"></span> 
 <span id="span44"></span> <span id="span45"></span>
    <span id="span46"></span> <span id="span47"></span><br>
 随机号码5：<span id="span51"></span> <span id="span52"></span> <span id="span53"></span> 
 <span id="span"></span> <span id="span55"></span>
    <span id="span56"></span> <span id="span57"></span><br>
 </p>
 <p class="oneStyle">
 排序后码1：<span id="span61"></span> <span id="span62"></span> <span id="span63"></span> 
 <span id="span"></span> <span id="span65"></span>
    <span id="span66"></span> <span id="span67"></span><br>
 排序后码2：<span id="span71"></span> <span id="span72"></span> <span id="span73"></span> 
 <span id="span74"></span> <span id="span75"></span>
    <span id="span76"></span> <span id="span77"></span><br>
 排序后码3：<span id="span81"></span> <span id="span82"></span> <span id="span83"></span> 
 <span id="span84"></span> <span id="span85"></span>
    <span id="span86"></span> <span id="span87"></span><br>
 排序后码4：<span id="span91"></span> <span id="span92"></span> <span id="span93"></span> 
 <span id="span94"></span> <span id="span95"></span>
    <span id="span96"></span> <span id="span97"></span><br>
 排序后码5：<span id="span101"></span> <span id="span102"></span> <span id="span103"></span> 
 <span id="span104"></span> <span id="span105"></span>
    <span id="span106"></span> <span id="span107"></span><br>
 </p>
 <p style="text-align:center">
 <input class="buttonStyle" id="fiveNumber" type="button" onclick="number()">
 </p>
 </p>
 <script type="text/javascript">
 var table = document.getElementById("table"); 
 var width = document.documentElement.clientWidth; //浏览器可见区域宽
 var height = document.documentElement.clientHeight; //浏览器可见区域高 
 table.style.marginLeft = ((width-800)/2)+"px"; 
 table.style.marginTop = ((height-700)/2)+"px";
 var val = "1";
 document.getElementById("fiveNumber").setAttribute("title","生成 1 组号码");
 document.getElementById("fiveNumber").setAttribute("value","生成 1 组号码"); 
 //随机生成五组号码
 function select()
 {
 val = document.getElementById("zushu").value; 
 var des = "生成 " + val + " 组号码";
 document.getElementById("fiveNumber").setAttribute("title",des);
 document.getElementById("fiveNumber").setAttribute("value",des);
 } //随机生成五组号码
 function number()
 { for(var n=1;n<11;n++){ 
 for(var m=1;m<8;m++){ 
 var a = "span" + n + m;
 document.getElementById(a).innerText = "";//每次点击按钮先清空上一次数据 
 document.getElementById(a).style.backgroundColor = "white";
 }
 } for(var x=1;x<(parseInt(val)+1);x++){ //从35个号码里面无放回地取5位
 var arr35 = ["01","02","03","04","05","06","07","08","09","10","11","12","13","14","15","16","17", 
 "18","19","20","21","22","23","24","25","26","27","28","29","30","31","32","33","34","35"]; 
 //从12个号码里面无放回地取2位
 var arr12 = ["01","02","03","04","05","06","07","08","09","10","11","12"]; 
 var span = ""; 
 var temp = ""; 
 for(var i=1;i<6;i++){
 span = "span" + x + i;
 temp = Math.floor(Math.random()*arr35.length);//随机取一个数 
 document.getElementById(span).innerText = arr35[temp];
 document.getElementById(span).style.backgroundColor = "red";
 arr35.splice(temp,1);//删除该位置的值 
 } 
 for(var j=6;j<8;j++){
 span = "span" + x + j;
 temp = Math.floor(Math.random()*arr12.length);//随机取一个数 
 document.getElementById(span).innerText = arr12[temp];
 document.getElementById(span).style.backgroundColor = "blue";
 arr12.splice(temp,1);//删除该位置的值 
 }
 } 
 for(var x=1;x<(parseInt(val)+1);x++){ 
 var span = ""; //前五位排序
 var arr = new Array(5); 
 for(var y=0;y<5;y++){
 span = "span" + x + (y+1);
 arr[y] = document.getElementById(span).lastChild.nodeValue;
 } var a = bubbleSort(arr); 
 for(var l=0;l<5;l++){
 span = "span" + (x+5) + (l+1);
 document.getElementById(span).innerText = a[l];
 document.getElementById(span).style.backgroundColor = "red";
 } //后两位排序
 var spann6 = "span" + x + "6"; 
 var spann7 = "span" + x + "7"; 
 var spanm6 = "span" + (x+5) + "6"; 
 var spanm7 = "span" + (x+5) + "7"; 
 var span6 = document.getElementById(spann6).lastChild.nodeValue; 
 var span7 = document.getElementById(spann7).lastChild.nodeValue; 
 if(parseInt(span6) > parseInt(span7)){
 document.getElementById(spanm6).innerText = span7;
 document.getElementById(spanm7).innerText = span6;
 }else{
 document.getElementById(spanm6).innerText = span6;
 document.getElementById(spanm7).innerText = span7;
 }
 document.getElementById(spanm6).style.backgroundColor = "blue";
 document.getElementById(spanm7).style.backgroundColor = "blue";
 }
 } //插入排序
 function bubbleSort(array){ 
 var len = array.length; 
 for (var i = 0; i < len; i++) { 
 for (var j = i; j > 0 && array[j]<array[j-1]; j--) { 
 var swap = array[j]; //第二个for循环使元素比较并移动到合适位置 
 array[j] = array[j-1];
 
 array[j-1] = swap;
 }
 } return array;
 } </script></body></html>

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