$num = 10.4567; //第一种：利用round()对浮点数进行四舍五入 echo round($num,2); //10.46 //第二种：利用sprintf格式化字符串 推荐使用第二种 如果$num = 10 输出$num = 10.00 $format_num = sprintf("%.2f",$num); echo $format_num; //10.46 //第三种：利用千位分组来格式化数字的函数number_format() echo number_format($num, 2); //10.46 echo number_format($num, 2, '.', ''); //10.46