I have a situation where I'm receiving an enum from an external system, and for which I need to return an enum of our own. The two enums have the exact same literal values in them: // externalEnum is guaranteed not to be null public static MyEnum enumToEnum(final Enum<? extends Enum<?>> externalEnum) { if( externalEnum instanceof M...
Assume InvalidResourceException is a subclass of ResourceException. Define two methods: void handleException(ResourceException e) { System.out.println("ResourceException " + e.toString()); } void handleException(InvalidResourceException e) { System.out.println("InvalidResourceException " + e.toString()); } Now the following code:...
Hello, I coded in NetBeans something like this: public class Grafo<V, E> { class Par { int a, b; Par(int a, int b) { this.a = a; this.b = b; } @Override public boolean equals(Object ob) { if(ob instanceof Par) { Par p = (Par)ob;...
Possible Duplicate: Python decorator makes function forget that it belongs to a class Is there a way to know that wrapped method belongs to particular class? In code below: def guessname(func): def this(*args, **kwargs): print "myname = %s" % func.__name__ return func(*args, **kwargs) return this class...
I'm trying to use some of the more advanced OO features of Javascript, following Doug Crawford's "super constructor" pattern. However, I don't know how to set and get types from my objects using Javascript's native type system. Here's how I have it now: function createBicycle(tires) { var that = {}; that.tires = tires; that....
Hi, Imagine, I want to write a useless method called: isInstanceof that returns a boolean. I was thinking about it. But I do not get out. An instanceof has to be used like: [object] instanceof [a classname] // I was thinking about something like this public static boolean isInstanceof(Object obj, /*magic for the second param*/) { r...
I am trying to figure out how to apply the is operand or the instanceof in a case statement to determine which datatype a interface object belongs too. keep getting errors switch (IOjbect is) { case Tile: trace ("Load Tile"); break; case House: trace ("A House Load...
I have following structure of objects: Animal, Dog and Cat. As You expect Dog and Cat are inherited from Animal. And I've a farm class: @implementation AnimalFarm -(Animal*) createAnimal:(AnimalType)type{ switch (type) { case CAT: return [Cat new]; case DOG: return [Dog new]; default: return [Anim...
Long l1 = null; Long l2 = Long.getLong("23"); Long l3 = Long.valueOf(23); System.out.println(l1 instanceof Long); // returns false System.out.println(l2 instanceof Long); // returns false System.out.println(l3 instanceof Long); // returns true I could not understand the output returned. I was expecting true atleast for 2nd and 3rd ...
Does the 'instanceof' keyword bear with it a relatively heavier impact on the Android platform (and more speciffically the mobile phones running the Dalvik VM)? Thank you. ...
Hi Everyone, I've been learning Java in my spare time and have a quick question I can't seem to figure out. This code returns true: Boolean testBool = true; Boolean test = testBool instanceof Object; System.out.println(test); However, I thought Boolean was a primitive type and when I try this same logic with any other primitive type...
interface If { ... } class Impl implements If { ... } function test(type:Class, obj) { return obj instanceof type; } test(If, new Impl()); The call to test on the last line returns false, but it should be true. How can I do this check right, with the requirement that it must be inside the function? Real code: public function...
In an android app test suite I have a class like this where B is a view: public class A extends B { ... etc... } now I have a list of view objects which may contain A objects but in this case I only care if they're subclasses or "instances of" B. I'd like to do something like: ArrayList<View> viewList = getViews(); Iterator<View> ite...
I need to test, if an instance is exactly of a given type. But it seems that instanceof returns true also if the subtype is tested for the supertype (case 3). I never knew this before and I am quite surprised. Am I doing something wrong here? How do I exactly test for a given type? //.. class DataSourceEmailAttachment extends EmailAtta...
What is the instanceof operator in JavaScript? I saw this in a blog post by John Resig, and didn't understand what does it means in regular JavaScript code (without that library). ...
Hi In some of my own older code, I use the following: Object.prototype.instanceOf = function( iface ) { return iface.prototype.isPrototypeOf( this ); }; Then I do (for example) [].instanceOf( Array ) This works, but it seems the following would do the same: [] instanceof Array Now, surly this is only a very simple example. My ...
The following compiles fine: Object o = new Object(); System.out.println(o instanceof Cloneable); But this doesn't: String s = new String(); System.out.println(s instanceof Cloneable); A compiler error is thrown. What is the problem? ...
Hi, could anyone tell me why this code won't compile? public boolean isOf(Class clazz, Object obj){ if(obj instanceof clazz){ return true; }else{ return false; } } Why I can't pass a class variable to instanceof? Thanks in advance. ...
Object[] o = new Object[]{}; System.out.println(o instanceof Cloneable); This gives true as o/p. I could not understand why? ...
Hello, Im overriding an equals() method and I need to know if the object is an instance of a Event's subclass (Event is the superclass). I want something like "obj subclassof Event". How can this be made? Thanks in advance! ...