js实现的格式化数字和金额功能简单示例

function number_format(number, decimals, dec_point, thousands_sep) {
 /*
 * 参数说明：
 * number：要格式化的数字
 * decimals：保留几位小数
 * dec_point：小数点符号
 * thousands_sep：千分位符号
 * */
 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(1234567.0, 2, ".", ",");//1,234,567.09
console.log(num);

function number_format(number, decimals, dec_point, thousands_sep) {
 /*
 * 参数说明：
 * number：要格式化的数字
 * decimals：保留几位小数
 * dec_point：小数点符号
 * thousands_sep：千分位符号
 * */
 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(1234567.0, 2, ".", ",");//1,234,567.08
console.log(num)