1：javascript 有符号右移0位用于取整。
1 var a = (-0.331*1) >> 0; 2 b = (-0.331*10) >> 0, 3 c = (-0.331*100) >> 0, 4 e = (0.331*1) >> 0, 5 f = (0.331*10) >> 0, 6 console.log(a);//0 7 console.log(b);//-3 8 console.log(c);//-33 9 console.log(e);//0 10 console.log(f);//3
原文：http://www.cnblogs.com/Hale-Proh/p/7072650.html