我最近开始学习PHP。
<?php
echo (int) ( (0.1+0.7) * 10 ); // prints '7', why not '8' ?
?>
请让我相信这个类型转换过程。
最佳答案
来自 PHP.net
It is typical that simple decimal fractions like 0.1 or 0.7 cannot be converted into their internal binary counterparts without a small loss of precision. This can lead to confusing results: for example, floor((0.1+0.7)*10) will usually return 7 instead of the expected 8, since the internal representation will be something like 7.9.
This is due to the fact that it is impossible to express some fractions in decimal notation with a finite number of digits. For instance, 1/3 in decimal form becomes 0.3.
关于php - 为什么此代码会打印 '7' 的结果？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/3150716/