FAQ Database Discussion Community

Are type hint and default param value also method signature?

Example : The interface is public function doFoo($bar); Can I have a class implementing the interface with method public function doFoo(array $bar = array('test')) { } What does the method signature mean in PHP? Is it just the method name and parameter name ? Or, type hinting and default values...

Changing signature while Overriding in C++

I have a base class class Shape{ public: virtual int getArea()=0; } I want to change the signature while overriding like this: class Rectangle : class Shape{ public: int getArea(int someParameter = 0){ return 0; } } Is it possible somehow to achieve this, as I am using default value...

Java Bytecode Signatures

As part of the compiler for the programming language I am working on, I came across generic signatures in the bytecode, which I am trying to parse and convert to an AST. The parsing algorithm mostly works, but there seems to be a special case in which the format of...

Why does Stream.Write not take a UInt?

It seems highly illogical to me that Stream.Write uses int, instead of UInt... Is there an explanation other than "legacy" code for this fact? Would any one want to write -1 bytes?!?

Why am I getting “onCreate(Bundle) already defined”?

I'm trying to produce several buttons which open different links but by copying the file over I get an error saying onCreate(Bundle) is already defined? Is it because I have two protected void onCreate(Bundle savedInstanceState) { or something? Please add a description to what is the issue and possibly an...

How to avoid calling a too much parameterized constructor, with virtual inheritance?

I want to perform a virtual inheritance with the following obvious example : class A { public: A(int a) : m_a(a) {} private: int m_a; }; class B : virtual public A { public: B(int a, int b) : A(a), m_b(b) {} private: int m_b; }; class C : virtual...

What's the principle to define an interface with dependencies?

Which dependency should locate in a method signature as a param and which should not? Since we have IoC container like spring, most of the dependencies could get injected through it. For java.util.concurrent.Executor: public interface Executor { void execute(Runnable command); } The interface could be public interface Executor { void...

Why does the Java equals(Object O) method not have a variant which can take a specific object type (e.g. String, Integer, etc) as input?

I come across problems where I need to compare two strings (or any other object ) for equality/non-equality using Java language. There are two methods on String Object very useful for this purpose viz. compareTo(Object O), which returns a integer result of comparison while other equals(Object o), which returns a...