function number_format(number, decimals, dec_point, thousands_sep) {  /*  * 參數(shù)說(shuō)明：  * number：要格式化的數(shù)字  * decimals：保留幾位小數(shù)  * dec_point：小數(shù)點(diǎn)符號(hào)  * thousands_sep：千分位符號(hào)  * */  number = (number + '').replace(/[^0-9+-Ee.]/g, '');  var n = !isFinite(+number) ? 0 : +number,    prec = !isFinite(+decimals) ? 0 : Math.abs(decimals),    sep = (typeof thousands_sep === 'undefined') ? ',' : thousands_sep,    dec = (typeof dec_point === 'undefined') ? '.' : dec_point,    s = '',    toFixedFix = function (n, prec) {      var k = Math.pow(10, prec);      return '' + Math.ceil(n * k) / k;    };  s = (prec ? toFixedFix(n, prec) : '' + Math.round(n)).split('.');  var re = /(-?/d+)(/d{3})/;  while (re.test(s[0])) {    s[0] = s[0].replace(re, "$1" + sep + "$2");  }  if ((s[1] || '').length < prec) {    s[1] = s[1] || '';    s[1] += new Array(prec - s[1].length + 1).join('0');  }  return s.join(dec);}

var num=number_format(1234567.089, 2, ".", ",");//1,234,567.09console.log(num);

function number_format(number, decimals, dec_point, thousands_sep) {    /*    * 參數(shù)說(shuō)明：    * number：要格式化的數(shù)字    * decimals：保留幾位小數(shù)    * dec_point：小數(shù)點(diǎn)符號(hào)    * thousands_sep：千分位符號(hào)    * */    number = (number + '').replace(/[^0-9+-Ee.]/g, '');    var n = !isFinite(+number) ? 0 : +number,      prec = !isFinite(+decimals) ? 0 : Math.abs(decimals),      sep = (typeof thousands_sep === 'undefined') ? ',' : thousands_sep,      dec = (typeof dec_point === 'undefined') ? '.' : dec_point,      s = '',      toFixedFix = function (n, prec) {        var k = Math.pow(10, prec);        return '' + Math.floor(n * k) / k;      };    s = (prec ? toFixedFix(n, prec) : '' + Math.floor(n)).split('.');    var re = /(-?/d+)(/d{3})/;    console.log(s)    while (re.test(s[0])) {      s[0] = s[0].replace(re, "$1" + sep + "$2");    }    if ((s[1] || '').length < prec) {      s[1] = s[1] || '';      s[1] += new Array(prec - s[1].length + 1).join('0');    }    return s.join(dec);}var num=number_format(1234567.089, 2, ".", ",");//1,234,567.08console.log(num)