如何保存指针最初指向的原始值

Question

新程序员在这里......任何帮助都将不胜感激......

在下面的示例中，我将如何保留原始值：0x4000000以便我执行以下操作： （int ）（0x4000000）= 900; 在将其更改为900或我决定在那里设置的任何值之前，我仍然可以将原始值设置为0x4000000 ....

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，代码apples == 10和*(int*)(0x4000000) == 900

之后

如果你做了

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

然后在结尾*apples将有900.你可以通过

来保存10

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。