c++ - 如何保存指针最初指向的原始值

Question

这里是新程序员...任何帮助将不胜感激...

在我下面的示例中，我将如何保留原始值:0x4000000，以便一旦我这样做:(int)(0x4000000) = 900;在我将其更改为 900 或我决定在那里设置的任何值之前，我仍然可以拥有 0x4000000 的原始值....

int apples = *(int*)(0x4000000);   // lets say that after doing this apples is assigned the value of 10(meaning 10 apples)
   // now how do i backup this original of value 10...
*(int*)(0x4000000) = 900;  // set the apples to 900 and go on... 

Answer 1

不，在你编码 apples == 10 和 *(int*)(0x4000000) == 900

之后

如果你做了

int *apples = (int*)(0x4000000);

然后在最后 *apples 将有 900 个。您可以通过以下操作节省 10 个

int apples_save = *apples; .

像这样

int *apples = (int*)(0x4000000);
int apples_save = *apples; .
*(int*)(0x4000000) = 900;

现在 *apples == 900 和 apples_save == 10 。