JS将数字转换成三位逗号分隔的样式(示例代码)_javascript技巧: 代码如下:function formatNum(num){ if(!/^(\+|-)(\d+)(\.\d+)$/.test(num)){alert(wrong!); return num;} var a = RegExp.$1, b = RegExp.$2, c = RegExp.$3; var re = new RegExp().com