instantiation

I'm new in programming and I would like to know where did I go wrong in instantiating an object. Below is the code: public class Testing{ private int Sample(int c) { int a = 1; int b = 2; c = a + b; return c; } public static void main(String []args) { Sample myTest = new Sample(); System.out.println(c); } } There is no Sample class in your code . The one which you have declared is a private method . // private method which takes an int as parameter and returns another int private int Sample(int c) { int a = 1; int b = 2; c = a + b; return c; } With the current snippet , You need to instantiate

the lazy thread-safe singleton instantion is kinda not easy to understand to every coder, so i wanted to create a class in our enterprise framework that would do the job. What do you think about it? Do you see something bad about it? Is there something similar like in Apache Commons? How can i make it better? Supplier.java public interface Supplier<T> { public T get(); } LazyThreadSafeInstantiator.java public class LazyThreadSafeInstantiator<T> implements Supplier<T> { private final Supplier<T> instanceSupplier; private volatile T obj; public LazyThreadSafeInstantiator(Supplier<T>

See title. I have a template. I want to force a particular instance of a template to instantiate. How do I do this? More specifically, can you force an abstract template class to instantiate? I might elaborate as I have the same question. In my case I am building a library, some of the template implementations are large and include lots of stuff, but are only generated for a couple of types. I want to compile them in the library and export all the methods, but not include the header with the code everywhere. ie: template<class T> OS_EXPORT_DECL class MyTmpl { T *item1; public: inline T

Under what conditions am I supposed to make the :base() and :this() constructor calls following my constructor's parentheses (or even in other places in the code). When are these calls good practices and when are they mandatory? Mark Byers : base(...) If you omit the call to a base constructor it will call the default base constructor automatically. It is mandatory to call a base constructor explicitly if there is no default constructor. Even if there is a default constructor you may still wish to call a different constructor than the default constructor. In this case you may still wish to use

I have a simple question: what's the advantage of instantiating a C# delegate as opposed to just passing the function reference? What I mean is: Why do: Thread t = new Thread(new ThreadStart(SomeObject.SomeMethod)); When you can do: Thread t = new Thread(SomeObject.SomeMethod); Both will compile and work in my experience...am I missing something? As long as the method group SomeObject.SomeMethod has a method with return type void and taking no parameters there is no difference. This is because ThreadStart is defined as a delegate that returns void and takes no parameters and therefore there is

Is there a way to circumvent the constructor __init__ of a class in python? Example: class A(object): def __init__(self): print "FAILURE" def Print(self): print "YEHAA" Now I would like to create an instance of A . It could look like this, however this syntax is not correct. a = A a.Print() EDIT: An even more complex example: Suppose I have an object C , which purpose it is to store one single parameter and do some computations with it. The parameter, however, is not passed as such but it is embedded in a huge parameter file. It could look something like this: class C(object): def __init__

I'm a C programmer trying to understand C++. Many tutorials demonstrate object instantiation using a snippet such as: Dog* sparky = new Dog(); which implies that later on you'll do: delete sparky; which makes sense. Now, in the case when dynamic memory allocation is unnecessary, is there any reason to use the above instead of Dog sparky; and let the destructor be called once sparky goes out of scope? Thanks! jalf On the contrary, you should always prefer stack allocations, to the extent that as a rule of thumb, you should never have new/delete in your user code. As you say, when the variable