class

问题 As far as I understand, Java Generics erases all the information concerning the parameter type T in the generic method (or in the generic class). That's why we can't use new expression, such as new T() instanceof expression, such as if(obj instanceof T) inside a generic method. My question is how the parameter type T works inside a generic method when it comes to casting. For example, I have 3 simple classes here: public class People { String name; public String getName() { return name; }

问题 I'm a student and I'm doing a static library for arrays in C++, so I don't have to rewrite code every time during lessons. I'm at second year in a secondary school so I'm not an expert. I want my code to be compatible with all type (int, float, ecc.) but I'm having some trouble. Can you give a look at my code? // slarray.h #if !defined _SLARRAY_ #define _SLARRAY_ template <typename Tipo> class Array { public: void inserisci(); void visualizza(); void copia(Tipo*); Array(short); ~Array();

问题 I'm a student and I'm doing a static library for arrays in C++, so I don't have to rewrite code every time during lessons. I'm at second year in a secondary school so I'm not an expert. I want my code to be compatible with all type (int, float, ecc.) but I'm having some trouble. Can you give a look at my code? // slarray.h #if !defined _SLARRAY_ #define _SLARRAY_ template <typename Tipo> class Array { public: void inserisci(); void visualizza(); void copia(Tipo*); Array(short); ~Array();

问题 First off, hello everyone! This is my first ever question here, so I hope I am not screwing up. I googled a lot before writing here. I am new to coding, to c++ and I am learning it on my own. Considering that I was told that it is a good practice (i'm probably wrong here) to only seed any Random Engine once, what is the proper / best / more efficient way of using std::mt19937 from the random standard library inside a class, seeded by std::chrono::high_resolution_clock::now().time_since_epoch(

问题 First off, hello everyone! This is my first ever question here, so I hope I am not screwing up. I googled a lot before writing here. I am new to coding, to c++ and I am learning it on my own. Considering that I was told that it is a good practice (i'm probably wrong here) to only seed any Random Engine once, what is the proper / best / more efficient way of using std::mt19937 from the random standard library inside a class, seeded by std::chrono::high_resolution_clock::now().time_since_epoch(

问题 I am writing a UTF-8 library for C++ as an exercise as this is my first real-world C++ code. So far, I've implemented concatenation, character indexing, parsing and encoding UTF-8 in a class called "ustring". It looks like it's working, but two seemingly equivalent ways of declaring a new ustring behave differently. The first way: ustring a; a = "test"; works, and the overloaded "=" operator parses the string into the class (which stores the Unicode strings as an dynamically allocated int

问题 I am writing a UTF-8 library for C++ as an exercise as this is my first real-world C++ code. So far, I've implemented concatenation, character indexing, parsing and encoding UTF-8 in a class called "ustring". It looks like it's working, but two seemingly equivalent ways of declaring a new ustring behave differently. The first way: ustring a; a = "test"; works, and the overloaded "=" operator parses the string into the class (which stores the Unicode strings as an dynamically allocated int

问题 I'm working with a fresh install of Lumen (building a web API), most things work but when i'm trying to use the router to point to a class i get this error: Fatal error: Class 'App\Http\Controllers\Controller' not found in /Applications/MAMP/htdocs/moments/lumen/app/Http/Controllers/MomentController.php on line 5 This is my router in app/Http/routes.php $app->get('/', 'MomentController@index'); And this is my class in app/Http/Controllers/MomentController.php <?php namespace App\Http

问题 my code is: public class Box { public static void main(String[] args) { Integer z = new Integer(43); z++; Integer h = new Integer(44); System.out.println("z == h -> " + (h == z )); } } Output:- z == h -> false why the output is false when the values of both the objects is equal? Is there any other way in which we can make the objects equal? 回答1: You are trying to compare two different object and not their values. z and h points to two different Integer object which hold same value. z == h

问题 I'm trying to build a generic class loader. I need to check classes that I load against a method argument to determine if they are of the same class. The code mostly explains what I'm trying to do. private static LinkedList<Object> loadObjectsInDirectory(Class class0, File dir) throws ClassNotFoundException { LinkedList<Feature> objects = new LinkedList<Object>(); ClassLoader cl = new GenericClassLoader(); for(String s : dir.list()) { Class class1 = cl.loadClass(s); try { Object x = class1