C语言 <<= 和 |= 的含义
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Meaning of <<= and |=
提问by SK9
What is the meaning of <<=and |=in C?
<<=和|=在C中是什么意思？
I recognise <<is bitshift etc. but I don't know what these are in combination.
我承认<<是 bitshift 等，但我不知道这些组合是什么。
回答by Chris Cooper
Just as x += 5means x = x + 5, so does x <<= 5mean x = x << 5.
正如x += 5手段x = x + 5，所以不x <<= 5平均x = x << 5。
Same goes for |. This is a bitwise or, so x |= 8would mean x = x | 8.
也一样|。这是一个按位or，所以x |= 8将意味着x = x | 8。
Here is an example to clarify:
这是一个澄清的例子：
int x = 1;
x <<= 2; // x = x << 2;
printf("%d", x); // prints 4 (0b001 becomes 0b100)
int y = 15;
y |= 8; // y = y | 8;
printf("%d", y); // prints 15, since (0b1111 | 0b1000 is 0b1111)
