不使用Math.random实现随机数

var rand = (``function``(){

var today = new Date();

var seed = today.getTime();

function rnd(){

seed = ( seed * 9301 + 49297 ) % 233280;

return seed / ( 233280.0 );

};

return function rand(number){

return Math.ceil(rnd(seed) * number);

};

})();

console.log(rand(100))

console.log(rand(100))

console.log(rand(100))

console.log(rand(100))

console.log(rand(100))

console.log(rand(100))

console.log(rand(100))

//原理参看这里 http://www.zhihu.com/question/22818104