| =运算符是什么意思？

Question

In some code i found this |= operator used to return a uint but i can find something about it on the internet and i wanna understand how it works and what are the return values in this case.

public uint Mask
{
    get
    {
        uint num = 0;
        if (_0)
            num |= 1U;
        if (_1)
            num |= 2U;
        if (_2)
            num |= 4U;
        return num;
    }
}

a detailed answer will be much appreciated.

Answer 1

You know how x += 1 means x = x + 1 , well x |= 1 means x = x | 1 x = x | 1 . Of course | means bitwise OR.