为什么我可以使用指针作为字符串使用双引号声明时，而不是大括号，在C？

问题描述

如果我声明和使用指针是这样的：

If I declare and use a pointer like this:

int counter;
char *pCow = "pCow goes MOO";

for(counter = 0; counter < 14; counter++)
    printf("%c", pCow[counter]);

它显示了整个字符串和作品，是的，并没有太多欣喜。

it displays the entire string and works and yeah and there is much rejoicing.

不过，如果我使用的初始化是这样的：

However, if I use an initializer like this:

int counter;
char *pCow = {'p','C','o','w',' ','g','o','e','s',' ','M','O','O','\0'};

for(counter = 0; counter < 14; counter++)
    printf("%c", pCow[counter]);

程序崩溃和pCow拒绝MOO我享乐主义的快乐！

the program crashes and pCow refuses to moo for my hedonistic pleasure!

3 Warnings. 0 Errors
line 11 (near initialization for 'pCow') [enabled by default]   C/C++ Problem
line 11 excess elements in scalar initializer [enabled by default]  C/C++ Problem
line 11 initialization makes pointer from integer without a cast [enabled by default]   C/C++ Problem

在精心Eclipse CDT的测试。

Lovingly tested in Eclipse CDT.

推荐答案

在这种情况下， pCow 设置为静态存储器中的C-字符串的地址：

In this case, pCow is set to the address of a c-string in static memory:

char *pCow = "pCow goes MOO";

在这种情况下， pCow 设置为值'P'（即 112 ）

In this case, pCow is set to the value 'p' (i.e., 112):

char *pCow = {'p','C','o','w',' ','g','o','e','s',' ','M','O','O','\0'};

由于地址 112 最有可能点入禁区/无效的内存，导致你的程序，当您尝试访问炸毁 pCow [计数器] 。

Since the address 112 most likely points into restricted/invalid memory, that causes your program to blow up when you try to access pCow[counter].

警告的标量初始化多余的元素的告诉你，这是无视后'P'所有的东西，因为指针只需要一个值。

The warning "excess elements in scalar initializer" is telling you that it's ignoring all of the stuff after the 'p' since the pointer only needs one value.

警告的初始化将指针从整数，未作类型转换的告诉你，你正在使用'P'为指针，这可能不是一个好主意......

The warning "initialization makes pointer from integer without a cast" is telling you that you're using 'p' as a pointer, which probably isn't a good idea...

您想要做的就是声明 pCow 为字符数组的而不是字符指针的，如果你想使用初始化语法：

What you want to do is declare pCow as a character array rather than a character pointer if you want to use the initializer syntax:

char pCow[] = {'p','C','o','w',' ','g','o','e','s',' ','M','O','O','\0'};

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