#include  int main(int argc,char *argv[]) { char str[] = "hello world"; printf("%s\n",str); return 0; }

The implicit declaration is because the header file is not included: stdio.h

yoursprintf参数用的是%c(字符)，而你想要打印的是字符串应该用%s。偏要打印%c，可以用printf("%c",str[0]);

main函数里没有定义返回值，默认为nt, and there is no return value at the end of the program, so the prompt

Warning: In a function with a return value, control flow reaches the end of the function [-Wreturn-type]

#include int main() { const char *h="Hello World!"; printf("%s\n",h); return 0; }

Actually, I think the error message is very obvious. As for %d, %c, %s, etc., the questioner should understand it himself.

If you can’t find the problem after reading this error message, then you need to reflect on it.

I have a few suggestions:

1. Take some time to study this book carefully. http://book.douban.com/subject/113933...
2. It is not recommended to use a Chinese environment, as it is not very beneficial for future reading and learning, etc. Personally, it is recommended to set the locale to en_US.UTF8.
3. Debugging, of course, requires mastering tools such as gdb. There should be some very good articles in coolshell.

%c is the output character
%s is the output string

The code is like the classmate above

There is an error in the program. To use strings in C, use arrays