指针 - 示例问题 [英] Pointers - sample question

问题描述

int main( ) {
 char str[] = { 48, 49, 50, 51, 52, 53, 54};
 int *p = (int *) (str + 1);
 char *pStr = (char *)p;
 printf("%c\n", *pStr);
}

什么是o / p？

在* p中存储什么，* pStr存储什么？

what is the o/p ?
in *p what gets stored and *pStr what gets stored?

推荐答案

试试吧！

编译它，运行它然后看看。



输出为1

p包含一个指向字符数组中第二个字节的指针

所以pStr。



如果你尝试实际使用p作为指向int的指针并从中检索整数值，可能会有所不同 - 某些系统会失败，因为int指针（可能）不是字对齐的。但char值不必具有任何特定的对齐方式，因此工作正常。

Try it!
Compile it, run it and see.

Output is "1"
p contains a pointer to the second byte in the array of characters
So does pStr.

It might be different if you try to actually use p as a pointer to an int and retrieve an integer value from it - some systems will fail, because the int pointer is (probably) not word aligned. But char values don''t have to have any particular alignment, so that works fine.

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