递增指针 [英] Incrementing Pointers

问题描述

我有一个关于增加指针的问题，我不太明白。

I have a question about incrementing in pointers that I dont quite understand.

我们看到两个小程序：

int iTuna=1;
int* pPointer= &iTuna;
*pPointer = *pPointer + 1 ; //Increment what pPointer is pointing to.
cout << iTuna << endl;

在这个第一个程序中，我递增pPointer指向的东西，像这样* pPointer = * pPointer +1 。
和我预期的iTuna改为2，程序打印出值2

In this first program I increment what pPointer is pointing to like this "*pPointer = *pPointer +1". And as I expected iTuna changed to "2" and the program printed out the value "2"

int iTuna=1;
int* pPointer= &iTuna;
*pPointer++; //Increment what pPointer is pointing to.
cout << iTuna << endl;
system("PAUSE");
return 0;

$ b $ p

这里我递增ppointer指向的是* pPointer ++。但这里iTuna保持为1，程序打印出值1。
虽然我期望这个工作作为第一个，它没有。

Here I incremented incremented what pPointer is pointing to this was "*pPointer++". But here iTuna stays as "1" and the programs prints out the value "1" . Although I expected this one to work as the first, it didn't.

请帮助我，告诉我为什么第二个代码不是

Please Help me and tell me why the second peice of code isn't working like I expected and how to get around it.

谢谢

推荐答案

*pPointer++;

相当于

*pPointer;
pPointer++; 

所以它递增指针，而不是解除引用的值。

so it increments the pointer, not the dereferenced value.

您可能会不时在字符串复制实现中看到这种情况，例如

You may see this from time to time in string copy implementations like

  while(*source)
    *target++ = *source++;

由于你的问题是运算符优先级的问题，如果你想deref指针， ，可以使用括号：

Since your problem is a matter of operator precedence, if you want to deref the pointer, and then increment, you can use parens:

(*pointer)++;

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