php round函数bug
算增长率的时候，用round来截取小数点后两位
但是后来去数据库看数据的时候，大部分数据都可以，但是有一部分出现错误
调试后发现
-8.04554643785644
round后变成
-8.04000000000001
这个bug出现几率还挺高
在另一个脚本中测试，同样的数据正常截取
回复内容：
算增长率的时候，用round来截取小数点后两位
但是后来去数据库看数据的时候，大部分数据都可以，但是有一部分出现错误
调试后发现
-8.04554643785644
round后变成
-8.04000000000001
这个bug出现几率还挺高
在另一个脚本中测试，同样的数据正常截取
不算bug吧，凡是涉及到浮点数问题肯定有精度误差的，用的时候注意一下就行了
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