奇怪的Delphi整数乘法行为 [英] Strange Delphi integer multiplication behavior

问题描述

我正在处理一些古老的Delphi代码，遇到了一些我不太了解的东西.

I'm working on some ancient Delphi code and I've come across something which I don't quite understand.

[bla is set to 130245932]

outresult := ((bla * 1103516849) + 12359);

[outresult is equal to -413953101]

两个正数相乘如何得出一个负数?为什么当我将bla变量从方程式中取出而直接使用整数(像这样)

How does multiplying two positive numbers result in a negative number? And why is it that when I take the bla variable out of the equation and just use the integer directly (like this)

outresult := ((130245932 * 1103516849) + 12359);

在应用编译之前我收到一个错误

I receive an error before the app even compiles

[DCC Error] Unit1.pas(60): E2099 Overflow in conversion or arithmetic operation

一些天才将不胜感激.谢谢.

Some genius would be appreciated. Thanks.

推荐答案

好的，我将其作为答案.

Alright, I'll make this an answer.

错误消息应该很清楚.您在这里有整数溢出:

The error message should be pretty clear. You have an integer overflow here:

130245932 * 1103516849

因为130245932 * 1103516849 = 143728580475708268太大，无法容纳32位整数.

because 130245932 * 1103516849 = 143728580475708268 which is too large to fit into a 32-bit integer.

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