为什么24 * 60 * 60 * 1000 * 1000除以24 * 60 * 60 * 1000在Java中不等于1000？ [英] why is 24 * 60 * 60 * 1000 * 1000 divided by 24 * 60 * 60 * 1000 not equal to 1000 in Java?

问题描述

为什么24 * 60 * 60 * 1000 * 1000除以24 * 60 * 60 * 1000在Java中不等于1000？

why is 24 * 60 * 60 * 1000 * 1000 divided by 24 * 60 * 60 * 1000 not equal to 1000 in Java?

推荐答案

因为乘法溢出32位整数。在64位中它没关系：

Because the multiplication overflows 32 bit integers. In 64 bits it's okay:

public class Test
{
    public static void main(String[] args)
    {
        int intProduct = 24 * 60 * 60 * 1000 * 1000;
        long longProduct = 24L * 60 * 60 * 1000 * 1000;
        System.out.println(intProduct); // Prints 500654080
        System.out.println(longProduct); // Prints 86400000000
   }
}

显然在乘法溢出后，分裂不会撤消溢出。

Obviously after the multiplication has overflowed, the division isn't going to "undo" that overflow.

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