overriding

问题 I was told that static methods are implicitly final and therefore can\'t be overridden. Is that true? Can someone give a better example of overriding a static method? If static methods are just class methods, what is the real use of having them? 回答1: (1) Static methods cannot be overridden, they can however be hidden using the 'new' keyword. Mostly overriding methods means you reference a base type and want to call a derived method. Since static's are part of the type and aren't subject to

问题 Just out of curiosity I tried overriding a abstract method in base class, and method the implementation abstract. As below: public abstract class FirstAbstract { public abstract void SomeMethod(); } public abstract class SecondAbstract : FirstAbstract { public abstract override void SomeMethod(); //?? what sense does this make? no implementaion would anyway force the derived classes to implement abstract method? } Curious to know why C# compiler allows writing \'abstract override\'. Isn\'t it

问题 Given the following code fragment, what are the differences in the function calls? What is function hiding? What is function overriding? How do they relate to function overloads? What is the difference between the two? I couldn\'t find a good description of these in one place, so I\'m asking here so I can consolidate the information. class Parent { public: void doA() { cout << \"doA in Parent\" << endl; } virtual void doB() { cout << \"doB in Parent\" << endl; } }; class Child : public Parent

问题 So, I\'m trying to figure out the best (most elegant with the least amount of code) way to allow overriding specific functions of a property (e.g., just the getter, just the setter, etc.) in python. I\'m a fan of the following way of doing properties, due to the fact that all of their methods are encapsulated in the same indented block of code (it\'s easier to see where the functions dealing with one property stop and the functions dealing with the next begin): @apply def foo(): \"\"\"A

问题 I am very confused about the concepts of polymorphism ,overloading and overriding because it seems same to me. Please explain these concepts, and how are they different from each other Very confused so please guide me properly. Thanks 回答1: Polymorphism can be achieved through overriding. Put in short words, polymorphism refers to the ability of an object to provide different behaviors (use different implementations) depending on its own nature. Specifically, depending on its position in the

问题 I am fairly new to CSS3 and I want to be able to do the following: When I add a class into a an element, it overrides the properties of another class used in this specific element. Let\'s say that I have <a class=\"left carousel-control\" href=\"#carousel\" data-slide=\"prev\"> I want to be able to add a class called bakground-none , that will over override the default background in the class left . Thanks! 回答1: There are different ways in which properties can be overridden. Assuming you have

问题 I have an application building against Android 2.1 and I want to override the back button. I have followed the example here: http://android-developers.blogspot.com/2009_12_01_archive.html And my code is as follows: @Override public boolean onKeyDown(int keyCode, KeyEvent event) { if (Integer.parseInt(android.os.Build.VERSION.SDK) < 5 && keyCode == KeyEvent.KEYCODE_BACK && event.getRepeatCount() == 0) { Log.d(\"CDA\", \"onKeyDown Called\"); onBackPressed(); } return true; } @Override public

问题 I have a parent class Parent and a child class Child , defined thus: class Parent { @MyAnnotation(\"hello\") void foo() { // implementation irrelevant } } class Child { @Override foo() { // implementation irrelevant } } If I obtain a Method reference to Child::foo , will childFoo.getAnnotation(MyAnnotation.class) give me @MyAnnotation ? Or will it be null ? I\'m interested more generally in how or whether annotation works with Java inheritance. 回答1: Copied verbatim from http://www.eclipse.org

问题 The generic entity, super class: @MappedSuperclass public abstract class GenericEntity { private Integer id; public Integer getId() {return id;} public void setId(Integer id) {this.id = id;} } The pojo: @Entity @Table(name = \"POJO_ONE\") @SequenceGenerator(name = \"HB_SEQ_POJO_ONE\", sequenceName = \"SEQ_POJO_ONE\", allocationSize = 1) public class PojoOne extends GenericEntity { @Id @GeneratedValue(strategy = GenerationType.SEQUENCE, generator = \"HB_SEQ_POJO_ONE\") @Column(name = \"ID\")

问题 I have an Ext.form.field.Text and I want to override the setValue function. What is the recommended way to override this class functionality in ExtJS? Ext.override? 回答1: For clarification: By real class modification I mean a intended permanent modification/extension of a class , which should always be done by extending a class. But it is not a temporary solution for just a specific problem (bug-fix, etc.) . You have at least four options how to override members of (Ext) Classes prototype I