This question was the subject of my blog on September 20th 2010. Josh and Chad’s answers (“they add no value so why require them?” and “to eliminate redundancy”) are basically correct. To flesh that out a bit more: The feature of allowing you to elide the argument list as part of the “larger feature” of … Read more
I think it’s a poor judgement on part of C# architects. readonly modifier on local variables helps maintain program correctness (just like asserts) and can potentially help the compiler optimize code (at least in the case of other languages). The fact that it’s disallowed in C# right now, is another argument that some of the … Read more
In high-level stuff, exceptions; in low-level stuff, error codes. The default behaviour of an exception is to unwind the stack and stop the program, if I’m writing a script an and I go for a key that’s not in a dictionary it’s probably an error, and I want the program to halt and let me … Read more
Here is how Matz(Yukihiro Matsumoto) explains it in an old thread: Hi, In message “[ruby-talk:02706] X++?” on 00/05/10, Aleksi Niemelä <aleksi.niemela@cinnober.com> writes: |I got an idea from http://www.pragprog.com:8080/rubyfaq/rubyfaq-5.html#ss5.3 |and thought to try. I didn’t manage to make “auto(in|de)crement” working so |could somebody help here? Does this contain some errors or is the idea |wrong? (1) … Read more
As damryfbfnetsi points out in the comments, JLS §14.11 has the following note: The prohibition against using null as a switch label prevents one from writing code that can never be executed. If the switch expression is of a reference type, that is, String or a boxed primitive type or an enum type, then a … Read more
Yuval and David’s answers are basically correct; summing up: Use of an unassigned local variable is a likely bug, and this can be detected by the compiler at low cost. Use of an unassigned field or array element is less likely a bug, and it is harder to detect the condition in the compiler. Therefore … Read more
protected methods can be called by any instance of the defining class or its subclasses. private methods can be called only from within the calling object. You cannot access another instance’s private methods directly. Here is a quick practical example: def compare_to(x) self.some_method <=> x.some_method end some_method cannot be private here. It must be protected … Read more
Many answers seem to focus on the ability to fall through as the reason for requiring the break statement. I believe it was simply a mistake, due largely because when C was designed there was not nearly as much experience with how these constructs would be used. Peter Van der Linden makes the case in … Read more
The definition of an inline function doesn’t have to be in a header file but, because of the one definition rule (ODR) for inline functions, an identical definition for the function must exist in every translation unit that uses it. The easiest way to achieve this is by putting the definition in a header file. … Read more
I think one reason it works this way is because access modifiers work at compile time. As such, determining whether or not a given object is also the current object isn’t easy to do. For example, consider this code: public class Foo { private int bar; public void Baz(Foo other) { other.bar = 2; } … Read more