整数乘法 [英] integer multiplication

问题描述

如果多个两个整数并且结果溢出了C中的

MAX_INT，会发生什么？有没有办法在条件发生时捕获它？

What happens if you multiple two integers and the result overflows the
MAX_INT in C? Is there a way to trap the condition when it happens?

推荐答案

Pesso写道：

Pesso wrote:

如果多个两个整数并且结果溢出了C中的

MAX_INT，会发生什么？

What happens if you multiple two integers and the result overflows the
MAX_INT in C?

有符号整数溢出时的行为取决于实现。

无符号整数不会溢出，但显示环绕行为

根据模2 ^ n算术。

Behaviour when signed integers overflow is implementation dependant.
Unsigned integers do not overflow, but exhibit "wrap-around" behaviour
according to modulo 2^n arithmetic.

有没有办法在条件发生时捕获条件？

Is there a way to trap the condition when it happens?

你必须看到你的实现文档。

标准并没有坚持陷阱。但请注意，在尝试之前，您可以轻松地检查特定操作是否会导致溢出或环绕

。这很乏味，但可以做到。

You''ll have to see your implementation''s documentation for this. The
Standard doesn''t insist on a trap. Note though, that you can easily
check if a particular operation will cause overflow or wrap-around
before attempting it. It''s tedious, but it can be done.

santosh写道：

santosh wrote:

Pesso写道：

Pesso wrote:

如果多个两个整数会导致结果溢出

MAX_INT在C中？

What happens if you multiple two integers and the result overflows the
MAX_INT in C?

有符号整数溢出时的行为取决于实现。

Behaviour when signed integers overflow is implementation dependant.

[...]


对不起，根据标准，它实际上是未定义的行为。 />

< snip>

[ ... ]

Sorry, it''s actually undefined behaviour, according to the Standard.

<snip>

Pesso说：

Pesso said:

如果多个两个整数并且结果溢出了C中的

MAX_INT，会发生什么？

What happens if you multiple two integers and the result overflows the
MAX_INT in C?

假设你的意思是整数和INT_MAX，行为是未定义的。

Assuming you mean ints and INT_MAX, the behaviour is undefined.

有没有办法陷阱它发生时的情况？

Is there a way to trap the condition when it happens?

不可移植，不。正确的技巧不是让它发生在第一名的
。这很容易避免。


-

Richard Heathfield

Usenet是一个奇怪的地方 - dmr 29/7/1999
http://www.cpax.org.uk

电子邮件：rjh在上述域名中， - www。

Not portably, no. The proper technique is not to let it happen in the
first place. It''s easy enough to avoid.

--
Richard Heathfield
"Usenet is a strange place" - dmr 29/7/1999
http://www.cpax.org.uk
email: rjh at the above domain, - www.

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