数据类型相关问题?-灵析社区

[muliplication expression *](https://link.segmentfault.com/?enc=Zb9w0hNM4zq06V009YOyYA%3D%3D.I2yCbLYidEzq2LKJTsqi1FRXToytj44s8y98IJ2YQI8qkL2Evw%2FF%2B6o3Sqxqzs9uKT4%2FvL1rSVyavKYyLXClfgQTzMpLYydc5YrAxPdNFyg%3D) > **If an integer multiplication overflows, then the result is the low-order > bits of the mathematical product as represented in some sufficiently large > two's-complement format.** As a result, if overflow occurs, then the sign of > the result may not be the same as the sign of the mathematical product of > the two operand values. 就是按照足够大的位数算一个精确结果，然后只取低位。 不同语言的规定会不太一样，所以要看语言自己的规定。 但是结果通常都是类似的，因为这样实现起来最方便。