1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
//随机数函数
function rnd() {
    rnd.seed = (rnd.seed*9301+49297) % 233280;
    return rnd.seed/(233280.0);
};
rnd.today=new Date();
rnd.seed=rnd.today.getTime();
function rand(number) {
    return Math.ceil(rnd()*number);
};
//测试
var r = [0,0,0,0];
for(var i=0; i<1000000; i++)
{
    var n = rand(3);
    ++r[n];
}
document.write(r[1]+'<br/>');
document.write(r[2]+'<br/>');
document.write(r[3]+'<br/>');