c# - 为什么这个按位或在可为空的 int 上返回 null？

Question

我基本上有以下内容:

    int? myVal = null;
    myVal |= 1;
    bool stillNull = myVal == null; //returns true

为什么会这样？我对按位运算符/操作数行为的理解不是很强，我找不到在这种情况下不将其视为简单赋值的理由。

Answer 1

来自 the documentation :

The predefined unary and binary operators or any overloaded operatorsthat are supported by a value type T are also supported by thecorresponding nullable value type T?. These operators, also known aslifted operators, produce null if one or both operands are null; otherwise, the operator uses the contained values of its operands to calculate the result.