不使用Math.random實現隨機數。

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)) //原理參看這里 http://www.zhihu.com/question/22818104