class

问题 I am generating C++ code based on a schema. There are entities and each entity contain attribute(s) with each attribute having a corresponding data type. Now the problem is some of these attributes are "optional", meaning that they do not have to be part of the class declaration. However, in C++, something is either a member of class or not a member of class, there is no concept such as "optional data member". Entities will be the class names, and attributes will be the class members. I am

问题 I'm working on a class that needs to be given it's __dict__ attribute via __init__ injection like this: class Torrent(Model): def __init__(self, d): super(Torrent, self).__init__('torrents') self.__dict__ = d And need to make sure not to change the structure of the object because the instance is going to end up in a NOSQL db. I thought that __slots__ could be helpful, but I need to define it dynamically. Is there a way to make it possible without a metaclass ? 回答1: Use a factory function: def

问题 toggleClass is great if I just have two presentations styles I want to use, but a lot of times I've got more than two states that I want to use. For example, if I want to rotate through three classes: if ($(this).hasClass("A")) $(this).removeClass("A").addClass("B"); else if ($(this).hasClass("B")) $(this).removeClass("B").addClass("C"); else if ($(this).hasClass("C")) $(this).removeClass("C").addClass("A"); I'd like to have a simple method that did this for me, something like: $(this)

问题 I am working on a database self project. I have an input file got from: http://ir.dcs.gla.ac.uk/resources/test_collections/cran/ After processing into 1400 separate file, each named 00001.txt ,... 01400.txt ...) and after applying Stemming on them, I will store them separately in a specific folder lets call it StemmedFolder with the following format: in StemmedFolder: 00001.txt includes: investig aerodynam wing slipstream brenckman experiment investig aerodynam wing in StemmedFolder: 00756

问题 Is there a way in Python to add to the locals name-space by calling a function without explicitly assigning variables locally? Something like the following for example (which of course doesn't work, because locals() return a copy of the local name-space) where the print statement would print '1'. def A(): B(locals()) print x def B(d): d['x'] = 1 回答1: In Python 2.* , you can disable the normal optimizations performed by the Python compiler regarding local variable access by starting your

问题 Is the any difference in performance and/or any other benefits we can get when using final keyword with constant utility class. [ This class contains only static final fields and private constructor to avoid object creation] public class ActionConstants { private ActionConstants() // Prevents instantiation { } public static final String VALIDFIRSTLASTNAME = "[A-Za-z0-9.\\s]+"; public static final String VALIDPHONENUMBER = "\\d{10}"; ... ... } Only diffrence is class is made final public final

问题 Is the any difference in performance and/or any other benefits we can get when using final keyword with constant utility class. [ This class contains only static final fields and private constructor to avoid object creation] public class ActionConstants { private ActionConstants() // Prevents instantiation { } public static final String VALIDFIRSTLASTNAME = "[A-Za-z0-9.\\s]+"; public static final String VALIDPHONENUMBER = "\\d{10}"; ... ... } Only diffrence is class is made final public final

问题 I can't figure out what the actual problem is with this. typedef struct _actor { ... } _actor, Actor; class Actor { ... }; I get this weird error message actor.cpp:31: error: using typedef-name ‘Actor’ after ‘class’ . Any idea what I did wrong here? Thank you :) 回答1: You are not allowed to define the symbol Actor more than once. The typedef statement already defines the symbol Actor as an alias for struct _actor before you attempt to declare a class with the same name. I'm guessing you're

问题 For example, a simple mvc type system: /api/class/method rewritten into php variables using .htaccess/nginx.conf then doing something like: <?php // Set up class + method variables $className = some_class_filter($_GET['class']); $method = some_method_filter($_GET['method']); // Check if class exists and execute if(file_exists(BASE . "/controllers/" . $className . ".class.php")) { require BASE . "/controllers/" . $className . ".class.php"; $$className = new $className(); // Execute the method

问题 Closed. This question is off-topic. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 4 years ago . I want to populate a class from a query. this is an example class: private class TVChannelObject { public string number { get; set; } public string title { get; set; } public string favoriteChannel { get; set; } public string description { get; set; } public string packageid { get; set; } public string format {