在 Java 中，A == B 和 B == A 始终具有相同的语义.在 C#(具有运算符重载)中，如果 B 是 A 类的子类的实例，则可能会有所不同.

In Java, A == B and B == A always have the same semantics. In C# (which has operator overloading), there can be a difference if, say, B is an instance of a subclass of the class of A.

请注意，A.equals(B) 不等同于 A == B.

Note that A.equals(B) is not equivalent to A == B.