《PHP实例：PHP中round()函数对浮点数进行四舍五入的方法》要点：
本文介绍了PHP实例：PHP中round()函数对浮点数进行四舍五入的方法，希望对您有用。如果有疑问，可以联系我们。
PHP学习本文实例讲述了PHP中round()函数对浮点数进行四舍五入的办法.分享给大家供大家参考.具体办法如下：
PHP学习语法:round(x,prec)
| 参数 |
描述 |
| x |
可选,规定要舍入的数字. |
| prec |
可选,规定小数点后的位数. |
PHP学习说明:返回将 x 根据指定精度 prec(十进制小数点后数字的数目)进行四舍五入的结果,prec 也可以是负数或零(默认值).
PHP学习提示和注释
PHP学习注释:php默认不能正确处理类似 "12,300.2" 的字符串.
PHP学习注释:prec 参数是在 php 4 中被引入的,实例代码如下:
代码如下:
<?php
*/
echo round(3.4); //输出3
echo "<br>";
echo round(3.5); //输出4
echo "<br>";
echo round(3.6); //输出4
echo "<br>";
echo round(3.6,0); //输出4
echo "<br>";
echo round(1.95583,2); //输出1.96
echo "<br>";
echo round(1241757,-3); //输出1242000
echo "<br>";
echo round(4.045,2); //输出4.05
echo "<br>";
echo round(4.055,2); //输出4.06
//使用stdround函数代替php的round函数
?>
代码如下:
<?php
function stdround($num, $d=0)
{
return round($num + 0.0001 / pow(10, $d), $d);
}
echo "round(1.005,2)= ".round(1.005,2). "n ";
echo "round(1.015,2)= ".round(1.015,2). "n ";
echo "round(1.025,2)= ".round(1.025,2). "n ";
echo "round(1.035,2)= ".round(1.035,2). "n ";
echo "round(1.045,2)= ".round(1.045,2). "n ";
echo "round(1.055,2)= ".round(1.055,2). "n ";
echo "round(1.065,2)= ".round(1.065,2). "n ";
echo "round(1.075,2)= ".round(1.075,2). "n ";
echo "round(1.085,2)= ".round(1.085,2). "n ";
echo "round(1.095,2)= ".round(1.095,2). "n ";
echo "stdround(1.005,2)= ".stdround(1.005,2). "n ";
echo "stdround(1.015,2)= ".stdround(1.015,2). "n ";
echo "stdround(1.025,2)= ".stdround(1.025,2). "n ";
echo "stdround(1.035,2)= ".stdround(1.035,2). "n ";
echo "stdround(1.045,2)= ".stdround(1.045,2). "n ";
echo "stdround(1.055,2)= ".stdround(1.055,2). "n ";
echo "stdround(1.065,2)= ".stdround(1.065,2). "n ";
echo "stdround(1.075,2)= ".stdround(1.075,2). "n ";
echo "stdround(1.085,2)= ".stdround(1.085,2). "n ";
echo "stdround(1.095,2)= ".stdround(1.095,2). "n ";
$m=0.000000000000001;
echo "n ";
echo "round(1.005+{$m},2)= ".round(1.005+$m,2). "n ";
echo "round(1.015+{$m},2)= ".round(1.015+$m,2). "n ";
echo "round(1.025+{$m},2)= ".round(1.025+$m,2). "n ";
echo "round(1.035+{$m},2)= ".round(1.035+$m,2). "n ";
echo "round(1.045+{$m},2)= ".round(1.045+$m,2). "n ";
echo "round(1.055+{$m},2)= ".round(1.055+$m,2). "n ";
echo "round(1.065+{$m},2)= ".round(1.065+$m,2). "n ";
echo "round(1.075+{$m},2)= ".round(1.075+$m,2). "n ";
echo "round(1.085+{$m},2)= ".round(1.085+$m,2). "n ";
echo "round(1.095+{$m},2)= ".round(1.095+$m,2). "n ";
echo "round(1.005,2)= ".round(1.005,2). "n ";
echo "round(1.015,2)= ".round(1.015,2). "n ";
echo "round(1.025,2)= ".round(1.025,2). "n ";
echo "round(1.035,2)= ".round(1.035,2). "n ";
echo "round(1.045,2)= ".round(1.045,2). "n ";
echo "round(1.055,2)= ".round(1.055,2). "n ";
echo "round(1.065,2)= ".round(1.065,2). "n ";
echo "round(1.075,2)= ".round(1.075,2). "n ";
echo "round(1.085,2)= ".round(1.085,2). "n ";
echo "round(1.095,2)= ".round(1.095,2). "n ";
?>
PHP学习希望本文所述对大家的PHP程序设计有所赞助.
《PHP实例：PHP中round()函数对浮点数进行四舍五入的方法》是否对您有启发，欢迎查看更多与《PHP实例：PHP中round()函数对浮点数进行四舍五入的方法》相关教程，学精学透。维易PHP学院为您提供精彩教程。
转载请注明本页网址：
http://www.vephp.com/jiaocheng/13881.html
