js如何不用随机函数生成一个随机数

js如何不用随机函数生成一个随机数

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Number('0x' + md5(Date.now()).slice(-8)) / 0xFFFFFFFF

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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);
  };
})();

原理见:http://www.zhihu.com/question/22818104