c - 如何确定将多字符char常量赋值给char变量的结果？

Question

为什么 char 变量从“ab”赋值中得到“b”，而不是“a”？

char c = 'ab';

printf("c: %c\n", c);

打印:

c: b

Answer 1

根据标准，它是实现定义的。来自 6.4.4.4 字符常量:

An integer character constant has type int. The value of an integer character constant containing a single character that maps to a single-byte execution character is the numerical value of the representation of the mapped character interpreted as an integer. 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.