char s[] 和 char *s 有什么区别? [英] What is the difference between char s[] and char *s?

问题描述

在 C 中，可以在如下声明中使用字符串文字:

In C, one can use a string literal in a declaration like this:

char s[] = "hello";

或者像这样:

char *s = "hello";

那么有什么区别呢?我想知道在编译和运行时的存储持续时间方面实际发生了什么.

So what is the difference? I want to know what actually happens in terms of storage duration, both at compile and run time.

推荐答案

这里的区别在于

char *s = "Hello world";

会将 "Hello world" 放在内存的只读部分，并使 s 成为一个指针，使任何写入对该内存的操作非法.

will place "Hello world" in the read-only parts of the memory, and making s a pointer to that makes any writing operation on this memory illegal.

在做的时候:

char s[] = "Hello world";

将文字字符串放在只读内存中，并将字符串复制到堆栈上新分配的内存中.从而使

puts the literal string in read-only memory and copies the string to newly allocated memory on the stack. Thus making

s[0] = 'J';

合法.

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