JavaScript生成20位随机字符串的完整实现

function s20(){ 
var data=["0","1","2","3","4","5","6","7","8","9","a","b","c","d","e","f"]; 
for(var j=0;j<500;j++){ //500为想要产生的行数
var result="";
for(var i=0;i<20;i++){ //产生20位就使i<20
r=Math.floor(Math.random()*16); //16为数组里面数据的数量，目的是以此当下标取数组data里的值！ 
result+=data[r]; //输出20次随机数的同时，让rrr加20次，就是20位的随机字符串了。 
} 
document.write(result); 
document.write("<br/>"); 
} }

<html> 
<head> 
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> 
<title></title> 
<script type="text/javascript"> 
function s20(){ 
var data=["0","1","2","3","4","5","6","7","8","9","a","b","c","d","e","f"]; 
for(var j=0;j<500;j++){ 
var result=""; 
for(var i=0;i<20;i++){ 
r=Math.floor(Math.random()*16);

result+=data[r]; 
} 
document.write(result); 
document.write("<br/>"); 
} } 
</script> 
</head> 
<body> 
<input type="button" onclick="s20()" value="产生随机数"> 
</body> 
</html>