jls

Consider the following example code class MyClass { public String var = "base"; public void printVar() { System.out.println(var); } } class MyDerivedClass extends MyClass { public String var = "derived"; public void printVar() { System.out.println(var); } } public class Binding { public static void main(String[] args) { MyClass base = new MyClass(); MyClass derived = new MyDerivedClass(); System.out.println(base.var); System.out.println(derived.var); base.printVar(); derived.printVar(); } } it gives the following output base base base derived Method calls are resolved at runtime and the

If one writes two public Java classes with the same case-insensitive name in different directories then both classes are not usable at runtime. (I tested this on Windows, Mac and Linux with several versions of the HotSpot JVM. I would not be surprised if there other JVMs where they are usable simultaneously.) For example, if I create a class named a and one named A like so: // lowercase/src/testcase/a.java package testcase; public class a { public static String myCase() { return "lower"; } } // uppercase/src/testcase/A.java package testcase; public class A { public static String myCase() {

To my understanding, the following code should have printed true . However, when I ran this code it is printing false . From Java docs of Anonymous Classes 15.9.5. : An anonymous class is always implicitly final public class Test { public static void main(String args[]) { Object o = new Object() { }; System.out.println("Annonymous class is final: " + Modifier.isFinal(o.getClass().getModifiers())); } } Can some one please help me understand this behavior. Note that the wording in the JLS of that particular section has changed significantly since then. It now (JLS 11) reads: 15.9.5. Anonymous

Given the following function call in C : fooFunc( barFunc(), bazFunc() ); The order of execution of barFunc and BazFunc is not specified, so barFunc() may be called before bazFunc() or bazFunc() before barFunc() in C . Does Java specify an order of execution of function argument expressions or like C is that unspecified? Michael Easter From the Java Language Specification (on Expressions): 15.7.4 Argument Lists are Evaluated Left-to-Right In a method or constructor invocation or class instance creation expression, argument expressions may appear within the parentheses, separated by commas.

I've noticed JLS talks of 5.1.10 Capture Conversion , but I fail to understand what they are. Can anyone explain them to me/give examples? Buhake Sindi Capture conversion was designed to make wildcards (in generics), ? useful. Suppose we have the following class: public interface Test<T> { public void shout(T whatever); public T repeatPreviousShout(); } and somewhere on our code we have, public static void instantTest(Test<?> test) { System.out.println(test.repeatPreviousShout()); } Because test is not a raw Test and since repeatPreviousShout() in "hindsight" returns a ? , the compiler knows

I am trying to simply test out the initialization safety of final fields as guaranteed by the JLS. It is for a paper I'm writing. However, I am unable to get it to 'fail' based on my current code. Can someone tell me what I'm doing wrong, or if this is just something I have to run over and over again and then see a failure with some unlucky timing? Here is my code: public class TestClass { final int x; int y; static TestClass f; public TestClass() { x = 3; y = 4; } static void writer() { TestClass.f = new TestClass(); } static void reader() { if (TestClass.f != null) { int i = TestClass.f.x; /