Implementing a simple random lottery applet based on JavaScript

Implementing a simple random lottery applet based on JavaScript_javascript skills

WBOY

Release： 2016-05-16 15:21:54

Original

1988 people have browsed it

It is more convenient to use tools such as VB, Delphi and other tools to implement small programs such as lottery. Since I do not have such an application installed on my machine, I can only find another way. In order to make the lottery program run directly on any machine without configuring the platform, the development tools and compilation and running tools can also be as simple as possible (such as text can be edited, and the browser that comes with the window system can be compiled and run) ) and decided to try using javascript. My research on JavaScript is not deep. It is mainly used in website development to judge the validity of data from the client (based on security considerations, websites with high security requirements try to use server-side languages to judge the validity of data). All involved are the most commonly used methods and functions. Therefore, the following programs can only be called relatively simple, and the interface effects and functions are very "simple".

The main key point is to get random numbers. To get random numbers within the specified range of numbers, use the formula (upper limit of range - lower limit of range + 1)*Math.random()+lower limit of range. The following is the source code:

<html> 
<head> 
<title> 抽奖小程序 </title> 
<!--javascript程序——Begin--> 
<script language="javascript"> 
//抽奖数字范围初始化 
var from=1; //起始值 
var to=1523; //终止值 
numarray=new Array(); //保存抽奖数字的数组 
flagarray=new Array(); //记录数字是否中奖的标示数组 
countaward=new Array(0,0,0); //记录每组抽奖次数，这里只抽三组奖 
/** 
函数名:sysInit 
传入参数:无 
返回值:ture/false 
功能:抽奖系统初始化,设定抽奖数字范围、初始化抽奖数字数组和标示数组 
*/ 
function sysInit() 
{ 
/*设定抽奖数字范围*/ 
//接受用户设定操作 
mixNum=prompt('起始值',1); 
maxNum=prompt('终止值',1523); 
//判断用户没有输入任何数据或输入空字符 
if(mixNum!=null&&maxNum!=null&&mixNum!=""&&maxNum!="") 
{ 
//判断用户输入的数据是否是合法的数字 
strTemp="0123456789"; 
for (i=0;i<(mixNum+maxNum).length;i++) 
{ 
j=strTemp.indexOf((mixNum+maxNum).charAt(i)); 
if (j==-1) 
{ 
alert("起始数字范围不正确,程序中断!"); 
return false; 
}//end if 
}//end for 
//若用户输入合法数字，则重新设定抽奖范围 
from=parseInt(mixNum); 
to=parseInt(maxNum); 
}//end if 
//初始化抽奖数字数组和标示数组 
for(i=0;i<(to-from);i++) 
{ 
numarray[i]=from+i; 
flagarray[i]=0; 
} 
//抽奖按钮有效 
first.disabled=false; 
second.disabled=false; 
third.disabled=false; 
return true; 
} 
/** 
函数名:getLuck 
传入参数:奖次award,此项奖总数awardtotal 
返回值:无 
功能:无重复抽取中奖数 
*/ 
function getLuck(award,awardtotal) 
{ 
var msg=""; 
//当抽奖数大于等于20个时,使用每次抽取10个中奖数。 
for(i=0;i<(awardtotal>=20&#63;10:1);i++) 
{ 
//设定循环抽取随机数并判断,防止数字重复取 
while(a=1) 
{ 
//判断提示某项奖已经取完 
if(countaward[award-1]==awardtotal) 
{ 
alert(award+"等奖已经取满"+awardtotal+"个"); 
return; 
} 
//在抽奖数字范围内抽取随机数 
lucky=Math.round((to-from+1)*Math.random()+from); 
//判断上面抽取的随机数是否已经取过 
if(numarray[lucky-from]==lucky&&flagarray[lucky-from]==0) 
{ 
flagarray[lucky-from]=award; 
countaward[award-1]++; 
msg+=award+"等奖N"+countaward[award-1]+":"+lucky+"\n"; 
break; 
}//end if 
}//end while 
}//end for 
alert(msg); 
return; 
} 
/** 
函数名:showLuck 
传入参数:无 
返回值:无 
功能:显示中奖的所有数 
*/ 
function showLuck() 
{ 
var str1="一等奖：<p>"; 
var str2="二等奖：<p>"; 
var str3="三等奖：<p>"; 
for(i=0;i<(to-from);i++) 
{ 
switch(flagarray[i]) 
{ 
case 1: 
str1=str1+numarray[i]+"<br>"; 
break; 
case 2: 
str2=str2+numarray[i]+"<br>"; 
break; 
case 3: 
str3=str3+numarray[i]+"<br>"; 
break; 
} 
} 
//显示三个奖项的中奖数 
document.write(str1); 
document.write(str2); 
document.write(str3); 
} 
</script> 
<!--javascript程序——End--> 
</head> 
<body> 
<center> 
<p><strong><font size="3" color="red">开始抽奖喽!!!</font></strong></p> 
<input type="button" name="range" value="设定抽奖系统" onclick="javascript:sysInit();"><p> 
<input type="button" name="first" value="抽取一等奖" disabled onclick="javascript:getLuck(1,3);"><p> 
<input type="button" name="second" value="抽取二等奖" disabled onclick="javascript:getLuck(2,20);"><p> 
<input type="button" name="third" value="抽取三等奖" disabled onclick="javascript:getLuck(3,100);"><p> 
<input type="button" name="show" value="显示抽奖结果" onclick="javascript:showLuck();"><p> 
</center> 
</body> 
</html>

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