我觉得更好的问题是你为什么觉得C欠你什么?C语言的设计是为了满足你的需要，仅此而已。你需要摆脱那种认为语言必须为你提供一切的心态。或者只是继续使用你的高级语言，这将给你奢侈的字符串，日历，容器;而在Java中，你会得到一种千变万化的东西。多个类型字符串，多个类型的unordered_map(s)。

这对你来说太糟糕了，这不是C的目的。C并不是被设计成一种从大头针到锚的臃肿语言。相反，您必须依赖第三方库或您自己的库。没有什么比创建一个包含字符串及其大小的简单结构体更容易的了。

struct String
{
 const char *s;
 size_t len;
};

你知道问题出在哪里。它不标准。另一种语言可能决定将len组织在字符串之前。另一种语言可能决定使用指针来代替结束。另一个人可能决定使用六个指针来提高String的效率。然而，null结尾的字符串是字符串的最标准格式;你可以用它来与任何语言进行交互。甚至Java JNI也使用以空结尾的字符串。

Lastly, it is a common saying; the right data structure for the task. If you find that need to know the size of a string more than anything else; well use a string structure that allows you to do that optimally. But don't make claims that that operation is used more than anything else for everybody. Like, why is knowing the size of a string more important than reading its contents. I find that reading the contents of a string is what I mostly do, so I use null terminated strings instead of std::string; which saves me 5 pointers on a GCC compiler. If I can even save 2 pointers that is good.

还有一点没有提到:当C语言被设计出来的时候，有很多机器的“char”不是8位的(即使是今天的DSP平台也不是8位的)。如果一个人决定字符串是长度前缀，应该使用多少'char'的长度前缀?使用two会人为地限制具有8位字符和32位寻址空间的机器的字符串长度，而在具有16位字符和16位寻址空间的机器上浪费空间。

If one wanted to allow arbitrary-length strings to be stored efficiently, and if 'char' were always 8-bits, one could--for some expense in speed and code size--define a scheme were a string prefixed by an even number N would be N/2 bytes long, a string prefixed by an odd value N and an even value M (reading backward) could be ((N-1) + M*char_max)/2, etc. and require that any buffer which claims to offer a certain amount of space to hold a string must allow enough bytes preceding that space to handle the maximum length. The fact that 'char' isn't always 8 bits, however, would complicate such a scheme, since the number of 'char' required to hold a string's length would vary depending upon the CPU architecture.

根据Joel Spolsky在这篇博文中的说法，

这是因为发明了UNIX和C编程语言的PDP-7微处理器有一个ascii字符串类型。ASCIZ的意思是“以Z(零)结尾的ASCII”。

在看到这里所有其他的答案后，我相信即使这是真的，这也只是C具有以空结束的“字符串”的部分原因。这篇文章很有启发性，因为像字符串这样简单的东西实际上是相当困难的。

空终止允许基于快速指针的操作。

我觉得更好的问题是你为什么觉得C欠你什么?C语言的设计是为了满足你的需要，仅此而已。你需要摆脱那种认为语言必须为你提供一切的心态。或者只是继续使用你的高级语言，这将给你奢侈的字符串，日历，容器;而在Java中，你会得到一种千变万化的东西。多个类型字符串，多个类型的unordered_map(s)。

这对你来说太糟糕了，这不是C的目的。C并不是被设计成一种从大头针到锚的臃肿语言。相反，您必须依赖第三方库或您自己的库。没有什么比创建一个包含字符串及其大小的简单结构体更容易的了。

struct String
{
 const char *s;
 size_t len;
};

你知道问题出在哪里。它不标准。另一种语言可能决定将len组织在字符串之前。另一种语言可能决定使用指针来代替结束。另一个人可能决定使用六个指针来提高String的效率。然而，null结尾的字符串是字符串的最标准格式;你可以用它来与任何语言进行交互。甚至Java JNI也使用以空结尾的字符串。

Lastly, it is a common saying; the right data structure for the task. If you find that need to know the size of a string more than anything else; well use a string structure that allows you to do that optimally. But don't make claims that that operation is used more than anything else for everybody. Like, why is knowing the size of a string more important than reading its contents. I find that reading the contents of a string is what I mostly do, so I use null terminated strings instead of std::string; which saves me 5 pointers on a GCC compiler. If I can even save 2 pointers that is good.

来自马的口

None of BCPL, B, or C supports character data strongly in the language; each treats strings much like vectors of integers and supplements general rules by a few conventions. In both BCPL and B a string literal denotes the address of a static area initialized with the characters of the string, packed into cells. In BCPL, the first packed byte contains the number of characters in the string; in B, there is no count and strings are terminated by a special character, which B spelled *e. This change was made partially to avoid the limitation on the length of a string caused by holding the count in an 8- or 9-bit slot, and partly because maintaining the count seemed, in our experience, less convenient than using a terminator.

Dennis M Ritchie, C语言的开发