1、c#用string.format
ToString("#,###.00")
2、js方法 转自http://www.cnblogs.com/cssfirefly/p/3582027.html
(1)
var num_s = "1232134456.546 "; alert(parseFloat(num_s).toLocaleString());
(2)
function format_number(nStr ){ nStr += ''; x = nStr.split('.'); x1 = x[0]; x2 = x.length > 1 ? '.' + x[1] : ''; var rgx = /(d+)(d{3})/; while (rgx.test(x1)) { x1 = x1.replace(rgx, '$1' + ',' + '$2'); } return x1 + x2; } var a="53669988.000"; alert(format_number(a)); alert(format_number("wahh")); alert(format_number(0)); alert(format_number(6698.0023));