strncpy不会自动补齐字符串结束符'\0'

str3里面初始部分是烫烫，那china是怎么来的？

str2[]={"China"},str3[6];
是str2的。

为什么str3里面会有str2?

我用手机是很难跟你说清楚的，你不把str3的'\0'补上会更奇怪的问题

这可是要把人问残呀，简单一点判断就行，当结果中出现一些奇怪的编码就是出错了呗。

char *strcat( char *strDestination, const char *strSource );
Return Value

Each of these functions returns the destination string (strDestination). No return value is reserved to indicate an error.

Parameters

strDestination

Null-terminated destination string

strSource

Null-terminated source string

Remarks

The strcat function appends strSource to strDestination and terminates the resulting string with a null character. The initial character of strSource overwrites the terminating null character of strDestination. No overflow checking is performed when strings are copied or appended. The behavior of strcat is undefined if the source and destination strings overlap.

感谢