//保留4位小数
var number = 12.3321432;
number = String(number).replace(/^(.*\..{4}).*$/,"$1");
number = Number(number); // number = 12.3321
//保留2位小数
var reg = /^(.*\..{2}).*$/;
var number2 = 12.3;
number2 = String(number2).replace(reg ,"$1");
number2 = Number(number2); // number2 = 12.3 不足保留位数不补0
标签：String,保留,number,js,number2,var,小数 From： https://www.cnblogs.com/cmooc/p/16772404.html