是否所有字符数组自动空值终止？ [英] Are all char arrays automatically null-terminated?

问题描述

也许我只是太转储谷歌上搜索，但我一直以为字符数组只得到空由字面初始化（终止字符X [] =ASDF; ），并得到了当我看到这似乎不是这样有些意外。

Probably I'm just too dump for googling, but I always thought char arrays get only null terminated by an literal initialization (char x[]="asdf";) and got a bit surprised when I saw that this seems not to be the case.

int main()
{
    char x[2];
    printf("%d", x[2]);
    return 0;
}

输出：0

不应该数组声明大小= 2 *的2个字符大小字符实际获得？还是我做错了什么吗？我的意思是并不鲜见使用一个char数组作为一个简单的字符数组，而不是一个字符串，或者是什么呢？

Shouldn't an array declared as size=2*char actually get the size of 2 chars? Or am I doing something wrong here? I mean it isn't uncommon to use a char array as a simple char array and not as a string, or is it?

推荐答案

您正在访问的范围之外的一个未初始化数组。这是双重的未定义行为的，什么事情都可能发生，甚至还让 0 作为输出。

You are accessing an uninitialized array outside its bounds. That's double undefined behavior, anything could happen, even getting 0 as output.

在回答你的真正问题：只有字符串得到的空值终止的，这意味着字符X [] =ASDF为 5 元素的数组。

In answer to your real question: Only string literals get null-terminated, and that means that char x[]="asdf" is an array of 5 elements.

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