oop

问题 Hey I'm a beginner programmer who is starting with python and am starting out by making a game in pygames. The game basically spawns in circles at random positions, and when clicked give you points. Recently i've hit a roadblock when I want to spawn in multiple instances of the same object(in this case circles) at the same time. I've tried stuff like sleep() and some other code related to counters, but it always results in the next circle spawned overriding the previous one(i.e the program

问题 I have a small task to create a Object Oriented PHP backend application which is to be used by an angular 7 frontend. This is a very small project with only few classes and my php project folder structure looks like, wamp/www/MyProject - MyObject.php - MyParser.php - index.php MyParser class looks like, <?php namespace app\parse; class MyParser { public static function parse_object(){ echo "in parse_object"; // --- parse logic--- } } And my index.php file looks like, <?php //---- some request

问题 I have my student S3 class # a constructor function for the "student" class student <- function(n,a,g) { # we can add our own integrity checks if(g>4 || g<0) stop("GPA must be between 0 and 4") value <- list(name = n, age = a, GPA = g) # class can be set using class() or attr() function attr(value, "class") <- "student" value } I want to define the class groupofstudents : stud1 <- student("name1", 20, 2.5) stud2 <- student("name2", 21, 3.5) groupofstudents <- function(firststud = stud1,

问题 Given this struct with a private stateful variable: struct Calibrate { private: Stitcher stitcher_obj_; } This is the stitcher object (with empty constructor): Stitcher::Stitcher(const std::vector<cv::Mat> &src_images){} When calling Calibrate , I am getting this error: default constructor of 'Calibrate' is implicitly deleted because field 'stitcher_obj_' has no default constructor Stitcher stitcher_obj_ ^ Thanks for any suggestions on how to fix this! 回答1: As soon as you provide a custom

问题 I was wondering whether it is possible to place the actual subroutines behind type bound procedures and the type definition in different files. EG: File A: Module TypeDef Type :: Test Integer :: a,b,c contains Procedure, Pass, Public :: add => SubAdd End Type Type(Test) :: Test Interface Subroutine SubAdd(this) Import TypeDef Class(TypeDef), Intent(InOut) :: this End Subroutine End Interface End Module File B: Module TypeRoutines use TypeDef Private :: SubAdd contains Subroutine SubAdd(this)

问题 I was wondering whether it is possible to place the actual subroutines behind type bound procedures and the type definition in different files. EG: File A: Module TypeDef Type :: Test Integer :: a,b,c contains Procedure, Pass, Public :: add => SubAdd End Type Type(Test) :: Test Interface Subroutine SubAdd(this) Import TypeDef Class(TypeDef), Intent(InOut) :: this End Subroutine End Interface End Module File B: Module TypeRoutines use TypeDef Private :: SubAdd contains Subroutine SubAdd(this)

问题 I was wondering whether it is possible to place the actual subroutines behind type bound procedures and the type definition in different files. EG: File A: Module TypeDef Type :: Test Integer :: a,b,c contains Procedure, Pass, Public :: add => SubAdd End Type Type(Test) :: Test Interface Subroutine SubAdd(this) Import TypeDef Class(TypeDef), Intent(InOut) :: this End Subroutine End Interface End Module File B: Module TypeRoutines use TypeDef Private :: SubAdd contains Subroutine SubAdd(this)

问题 I'm fiddling around with proper overriding of virtual methods. I chain some constructors and in the base class constructor I call a virtual method. Call chain should be as followed: B(p)->A(p)->B.foo(p) Call chain is in C++: B(p)->A(p)->A.foo(p) Call chain is in C#: B(p)->A(p)->B.foo(p) So in other words, in C# behaviour is like expected, in C++ it isn't. C++ Code: #include <cstdio> class A { public: A(); A(int); virtual void foo(int s); }; class B : public A { public: B(); B(int s) : A(s) {}

问题 I'm fiddling around with proper overriding of virtual methods. I chain some constructors and in the base class constructor I call a virtual method. Call chain should be as followed: B(p)->A(p)->B.foo(p) Call chain is in C++: B(p)->A(p)->A.foo(p) Call chain is in C#: B(p)->A(p)->B.foo(p) So in other words, in C# behaviour is like expected, in C++ it isn't. C++ Code: #include <cstdio> class A { public: A(); A(int); virtual void foo(int s); }; class B : public A { public: B(); B(int s) : A(s) {}

问题 I'm fiddling around with proper overriding of virtual methods. I chain some constructors and in the base class constructor I call a virtual method. Call chain should be as followed: B(p)->A(p)->B.foo(p) Call chain is in C++: B(p)->A(p)->A.foo(p) Call chain is in C#: B(p)->A(p)->B.foo(p) So in other words, in C# behaviour is like expected, in C++ it isn't. C++ Code: #include <cstdio> class A { public: A(); A(int); virtual void foo(int s); }; class B : public A { public: B(); B(int s) : A(s) {}