"The value of an integer character constant containing more than one character (e.g., 'ab'), or containing a character or escape sequence that does not map to a single-byte execution character, is implementation-defined."
An ordinary character literal that contains more than one c-char is a multicharacter literal. A multicharacter literal has type int and implementation-defined value.
它的值由编译器(的实现)决定,没有确定结果。 也就说,避免使用它。 你就不必深究了。
关于字节序:搜索byte order 关于内存对齐方式(填充方式):搜索memory alignment