equals

问题 This question already has answers here : Why are two AtomicIntegers never equal? (9 answers) The right way to do equals and hashcode of objects held by AtomicReference (3 answers) Closed 9 months ago . I started using AtomicReference in Java beans to have the 3state semantic when reading objects from JSON. As I like to have equals and hashCode implementations in my beans I'm wondering why AtomicReference doesn't override equals. The implementation would be trivial (simply delegate to the

问题 Many people don't like to use instanceof , but I find that in many cases we have few other options when it comes to the equals method. Take a look at the class below: class A { int n; public A(int n) { this.n = n; } @Override public boolean equals(Object o) { return false; } public boolean equals(A o) { return n == o.n; } } I've never seen something like this done, but could it serve as a replacement for having to use instanceof to test if an Object is an A ? Or are there other problems that

来源： https://stackoverflow.com/questions/56908063/how-to-use-equalsandhashcode-with-include-lombok

来源： https://stackoverflow.com/questions/56908063/how-to-use-equalsandhashcode-with-include-lombok

问题 Why is structural equality comparison affected, after deserialisation to case class instance, by the location of case class definition being inside or outside another class. For example, the assertion in the following snippet package example import org.json4s.DefaultFormats import org.json4s.native.JsonMethods.parse class Foo { case class Person(name: String) def bar = { implicit val formats = DefaultFormats val expected = Person(name = "picard") val actual = parse("""{"name": "picard"}""")

问题 Why is structural equality comparison affected, after deserialisation to case class instance, by the location of case class definition being inside or outside another class. For example, the assertion in the following snippet package example import org.json4s.DefaultFormats import org.json4s.native.JsonMethods.parse class Foo { case class Person(name: String) def bar = { implicit val formats = DefaultFormats val expected = Person(name = "picard") val actual = parse("""{"name": "picard"}""")

问题 Why is structural equality comparison affected, after deserialisation to case class instance, by the location of case class definition being inside or outside another class. For example, the assertion in the following snippet package example import org.json4s.DefaultFormats import org.json4s.native.JsonMethods.parse class Foo { case class Person(name: String) def bar = { implicit val formats = DefaultFormats val expected = Person(name = "picard") val actual = parse("""{"name": "picard"}""")

问题 I'm working my way through the 3rd edition of Eloquent JavaScript and although I've seen one or two various answers on SO that seem almost identical in execution logic to mine that work mine just doesnt seem to no matter how I tweek it. THE GOAL: create a deep comparison function that can compare two objects and determine based on their properties if theyre different instances of the same type of object (same keys and values) regardless of reference... Can anyone spot the bug in my code?

问题 J. Bloch in his effective Java provides a several rules for the implementation for equals method. Here they are: • Reflexive: For any non-null reference value x, x.equals(x) must return true. • Symmetric: For any non-null reference values x and y, x.equals(y) must return true if and only if y.equals(x) returns true. • Transitive: For any non-null reference values x, y, z, if x.equals(y) returns true and y.equals(z) returns true, then x.equals(z) must return true. • Consistent: For any non

问题 I was digging around in ILDASM and Reflector as found that: == is compiled to the "ceq" MSIL command object.Equals is left as is object.Equals calls object.InternalEquals This question showed me how to find out how InternalEquals might be implemented i.e. in .cpp class (or whatever, somewhere in the CLR). My question is: What does ceq become? Another method in a different .cpp class? I.e. they are completely different peices of code? So although the default behaviour of == and Equals appears