In line with the other answers, there are multiple ways to call super class methods (including the constructor), however in Python-3.x the process has been simplified: Python-3.x class A(object): def __init__(self): print(“world”) class B(A): def __init__(self): print(“hello”) super().__init__() Python-2.x In python 2.x, you have to call the slightly more verbose version super(<containing classname>, self), which … Read more
>>> class new_class(): … def __init__(self, number): … self.multi = int(number) * 2 … self.str = str(number) … >>> a = new_class(2) >>> a.__dict__ {‘multi’: 4, ‘str’: ‘2’} >>> a.__dict__.keys() dict_keys([‘multi’, ‘str’]) You may also find pprint helpful.
You forget the tricky 2nd difference between classes and structs. Quoth the standard (ยง11.2.2 in C++98 through C++11): In absence of an access-specifier for a base class, public is assumed when the derived class is declared struct and private is assumed when the class is declared class. And just for completeness’ sake, the more widely … Read more
You have to define your static member outside the class definition and provide the initializer there. First // In a header file (if it is in a header file in your case) class A { private: static const string RECTANGLE; }; and then // In one of the implementation files const string A::RECTANGLE = “rectangle”; … Read more
Update: See others answer, this is outdated. Short answer, no, there is no native support for private properties with ES6 classes. But you could mimic that behaviour by not attaching the new properties to the object, but keeping them inside a class constructor, and use getters and setters to reach the hidden properties. Note that … Read more
2018 update: There is now a stage 3 proposal – I am looking forward to make this answer obsolete in a few months. In the meantime anyone using TypeScript or babel can use the syntax: varName = value Inside a class declaration/expression body and it will define a variable. Hopefully in a few months/weeks I’ll … Read more
According to the very popular WWDC 2015 talk Protocol Oriented Programming in Swift (video, transcript), Swift provides a number of features that make structs better than classes in many circumstances. Structs are preferable if they are relatively small and copiable because copying is way safer than having multiple references to the same instance as happens … Read more
In order to access private fields, you need to get them from the class’s declared fields and then make them accessible: Field f = obj.getClass().getDeclaredField(“stuffIWant”); //NoSuchFieldException f.setAccessible(true); Hashtable iWantThis = (Hashtable) f.get(obj); //IllegalAccessException EDIT: as has been commented by aperkins, both accessing the field, setting it as accessible and retrieving the value can throw Exceptions, … Read more
The reason you need to use self. is because Python does not use special syntax to refer to instance attributes. Python decided to do methods in a way that makes the instance to which the method belongs be passed automatically, but not received automatically: the first parameter of methods is the instance the method is … Read more
The biggest use of partial classes is to make life easier for code generators / designers. Partial classes allow the generator to simply emit the code they need to emit and they do not have to deal with user edits to the file. Users are likewise free to annotate the class with new members by … Read more