php5和php7的bcadd计算精度区别

拼搏现实的明天。 2023-10-09 04:13 47阅读 0赞

php7(PHP 7.3.2)的代码如下所示:

具体代码如下所示：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2diNDIxNTI4Nw_size_16_color_FFFFFF_t_70][]

$redis\_arr\['money'\] = 3708;  
$moremoneyRes\['money'\] = 88.49;  
$moneyData\['money'\] = bcadd($redis\_arr\['money'\],$moremoneyRes\['money'\],2);  
var\_dump($moneyData\['money'\]);

执行结果如下所示：

![20190925105600740.png][]

php5（PHP 5.4.39）的代码如下所示:

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2diNDIxNTI4Nw_size_16_color_FFFFFF_t_70 1][]

public function test2() \{  
$redis\_arr\['money'\] = 3708;  
$moremoneyRes\['money'\] = 88.49;  
$moneyData\['money'\] = bcadd($redis\_arr\['money'\],$moremoneyRes\['money'\],2);  
var\_dump($moneyData\['money'\]);  
\}

运行结果如下所示：

![20190925105835366.png][]

$redis\_arr\['money'\] = 3891.11和$moremoneyRes\['money'\] = 9.78也会有同样的问题。

解决方案用sprintf代替。

$moneyData\['money'\] = sprintf("%.2f",$redis\_arr\['money'\]+$moremoneyRes\['money'\]);

PHP 7.3.2和PHP 5.4.39用bcadd函数有精度计算的差异。

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2diNDIxNTI4Nw_size_16_color_FFFFFF_t_70]: https://img-blog.csdnimg.cn/20190925105503754.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2diNDIxNTI4Nw==,size_16,color_FFFFFF,t_70
[20190925105600740.png]: https://img-blog.csdnimg.cn/20190925105600740.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2diNDIxNTI4Nw_size_16_color_FFFFFF_t_70 1]: https://img-blog.csdnimg.cn/20190925105709877.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2diNDIxNTI4Nw==,size_16,color_FFFFFF,t_70
[20190925105835366.png]: https://img-blog.csdnimg.cn/20190925105835366.png