千分位分隔符保留指定位数小数

//千分位分隔符 num:数字 len:保留小数点位数export function formatNumber(num,len) {num = num + "";if (!num.includes(".")) {num += ".";} else {num = Number(num).toFixed(len).toString();}let val = num.replace(/(\d)(?=(\d{3})+\.)/g, function ($0, $1) {return $1 + ",";}).replace(/\.$/, "");return val;}formatNumber(123456.3456, 2) //123,456.35formatNumber(123456.345643, 4) //123,456.3456