var possible = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
http://www.2cto.com/kf/201210/162522.html
有实例了直接搞他代码不就行了
function order(a){
var t="";while(a!=""){b=a.length;c=Math.floor(Math.random()*99999)%b;t+=a.substr(c,1);a=a.substr(0,c)+a.substring(c+1)}
return t.replace(/</g,"<");
}
var possible = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
possible=order(possible)
console.log(possible)