解决javascript四舍五入不准确

 function roundFixed(num, fixed) {
     var pos = num.toString().indexOf('.'),
         decimal_places = num.toString().length - pos - 1,
         _int = num * Math.pow(10, decimal_places),
         divisor_1 = Math.pow(10, decimal_places - fixed),
         divisor_2 = Math.pow(10, fixed);
     return Math.round(_int / divisor_1) / divisor_2;
 }

 console.log(roundFixed(3.135,2));//-> 3.14
 console.log(roundFixed(2.135,2));//-> 2.14
 console.log(roundFixed(0.955,1));//-> 1
 console.log(roundFixed(0.955,2));//-> 0.96
 console.log(roundFixed(1.955,2));//-> 1.96
 console.log(roundFixed(1.955,1));//-> 2

参考：http://bbs.csdn.net/topics/391957876  perhapschen的回答