字符数组的大小和字符指针的大小 [英] size of character array and size of character pointer

问题描述

我有件C code的，我不明白是怎么的sizeof（...）函数的工作原理：

I have a piece of C code and I don't understand how the sizeof(...) function works:

#include <stdio.h>

int main(){
   const char  firstname[] = "bobby";
   const char* lastname = "eraserhead";
   printf("%lu\n", sizeof(firstname) + sizeof(lastname));
   return 0;
}

在上面的code的sizeof（名字）是6和sizeof（姓氏）为8。

In the above code sizeof(firstname) is 6 and sizeof(lastname) is 8.

但鲍比宽5个字符和橡皮头 11宽。我期待 16 。

But bobby is 5 characters wide and eraserhead is 11 wide. I expect 16.

为什么sizeof的行为不同的字符数组和指针人物？

Why is sizeof behaving differently for the character array and pointer to character?

任何一个可以澄清？

推荐答案

姓是字符阵列背着尾随 0 终止子。 姓是一个指针。在64位系统中指针是8字节宽。

firstname is a char array carrying a trailing 0-terminator. lastname is a pointer. On a 64bit system pointers are 8 byte wide.

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