Static classes in Python
Generally, usage like this is better done by just using functions in a module, without a class at all.
instance
Can we create an object of an interface?
What you are seeing here is an anonymous inner class: Given the following interface: interface Inter { public String getString(); } You can create something like an instance of it like so: Inter instance = new Inter() { @Override public String getString() { return “HI”; } }; Now, you have an instance of the interface … Read more
How to copy/create derived class instance from a pointer to a polymorphic base class?
You add a virtual Base* clone() const = 0; in your base class and implement it appropriately in your Derived classes. If your Base is not abstract, you can of course call its copy-constructor, but that’s a bit dangerous: If you forget to implement it in a derived class, you’ll get (probably unwanted) slicing. If … Read more
Setting default/empty attributes for user classes in __init__
I think you should avoid both solutions. Simply because you should avoid to create uninitialized or partially initialized objects, except in one case I will outline later. Look at two slightly modified version of your class, with a setter and a getter: class MyClass1: def __init__(self, df): self.df = df self.results = None def set_results(self, … Read more
Create an instance of a React class from a string
This will not work: var Home = React.createClass({ … }); var Component = “Home”; React.render(<Component />, …); However, this will: var Home = React.createClass({ … }); var Component = Home; React.render(<Component />, …); So you simply need to find a way to map between the string “Home” and the component class Home. A simple object … Read more
Easiest way to copy/clone a mongoose document instance?
You need to reset d1.isNew = true; as in: Model.findById(yourid).exec( function(err, doc) { doc._id = new mongoose.Types.ObjectId(); doc.isNew = true; //<——————–IMPORTANT doc.save(callback); } );
How to test same object instance in Javascript?
You just need this if(c == a) { // same instance } a == b and b == c will return false
Multiple docker containers for mysql or one instance with multiple databases
Docker is especially suited to the deployment of microservices. The following links discuss two strategies with regard to the use of databases: Database per service Shared database I personally favour the use of a single database per service and extend that to the deployment of separate instances of a database server. This ensures services are … Read more
WPF Enforce only ONE instance of application
Old link no longer available :/: http://blogs.microsoft.co.il/blogs/arik/archive/2010/05/28/wpf-single-instance-application.aspx Suggest having at update posted by @sergio-basurco Doesn’t require VB.DLL as some other examples advise. Has WPF sample code. Passes any cmd line args to initial instance.
C# Get property value without creating instance?
Real answer: no. It’s an instance property, so you can only call it on an instance. You should either create an instance, or make the property static as shown in other answers. See MSDN for more information about the difference between static and instance members. Tongue-in-cheek but still correct answer: Is it possible to get … Read more