method-call

问题 I'm trying to call a boolean method in another class and Eclipse is reporting the above error on the second line in the following code: CCR ccrFlags = new CCR(); if (ccrFlags.cBit() = set) The method being called from the class called "CCR" is: public boolean cBit() { boolean set = false; return set; } I imagine I'm probably going about this in an idiotic way and would be grateful for any advice. Thanks, Robert. 回答1: Comparison should use == (double-equal): CCR ccrFlags = new CCR(); if

问题 I'm trying to call a boolean method in another class and Eclipse is reporting the above error on the second line in the following code: CCR ccrFlags = new CCR(); if (ccrFlags.cBit() = set) The method being called from the class called "CCR" is: public boolean cBit() { boolean set = false; return set; } I imagine I'm probably going about this in an idiotic way and would be grateful for any advice. Thanks, Robert. 回答1: Comparison should use == (double-equal): CCR ccrFlags = new CCR(); if

问题 I am trying to call a method stored as $_auto , but it will not work. <?php class Index { private $_auto; public function __construct() { $this->_auto = "index"; $this->_auto(); } public function index() { echo "index"; } } $index = new Index(); ?> 回答1: You need to use call_user_func to do this: call_user_func(array($this, $this->_auto)); Unfortunately PHP does not allow you to directly use property values as callables. There is also a trick you could use to auto-invoke callables like this. I

问题 If the generic type argument (of either a calling class or calling method) is constrained with where T : Base the new method in T == Derived is not called, instead the method in Base is called. Why is the type T ignored for method call even though it should be known before run time? Update : BUT, when the constraint is using an interface like where T : IBase the method in Base class is called (not the method in interface, which is also impossible). So that means the system actually is able to

问题 Perl has the feature that strings named like a file handle are taken to be a filehandle: # let this be some nice class I wrote package Input { sub awesome { ... } } So when we do Input->awesome or extra-careful: 'Input'->awesome , the method will get called. Unless: # now somewhere far, far away, in package main, somebody does this: open Input, "<&", \*STDIN or die $!; # normally we'd open to a file This code doesn't even have to be executed, but only be seen by the parser in order to have

问题 I hope the title actually describes what I wanted to ask... I wrote a piece of code that compiles with gcc and works as I intended. However, it does not compile with llvm and the code executes differently when compiled with icc! Here is an example of the problem: #include <iostream> using std::cout; using std::endl; class A { public: virtual void foo() { cout << "A::foo()" << endl; } }; class B : public A { public: typedef A base; virtual void foo() { cout << "B::foo()" << endl; } }; int main

问题 Suppose I have the following Class A { Foo getFoo(); Bar getBar(); Baz getBaz(); } And I need to define a function doStuff that uses Foo , Bar , Baz of one object and does some stuff I'm struggling between which method of implementing doStuff is better (suppose it would be undesirable to place doStuff inside class A ) Method A void doStuff(Foo foo, Bar bar, Baz baz) { //some operation } or Method B void doStuff(A a) { Foo foo = a.getFoo(); Bar bar = a.getBar(); Baz baz = a.getBaz(); //some

问题 I have this situation that when AbstractMethod method is invoked from ImplementClass I want to enforce that MustBeCalled method in the AbstractClass is invoked. I’ve never come across this situation before. Thank you! public abstract class AbstractClass { public abstract void AbstractMethod(); public void MustBeCalled() { //this must be called when AbstractMethod is invoked } } public class ImplementClass : AbstractClass { public override void AbstractMethod() { //when called, base

问题 I have to call a method inside the java swing actionperformed method. But when I click the button nothing happens. How to solve this problem? private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) { hellocalled(); } } 回答1: You need to add action listener to your button in order to respond to click event: Button b = new Button(); b.addActionListener(new ActionListener(){ public void actionPerformed(ActionEvent evt){ jButton1ActionPerformed(evt); // call the method

问题 How does getRequestDispatcher("xxx") get called from getServletContext() in the example below? How does calling procedures like this work in general? Please give me a clear picture about this context. RequestDispatcher dispatcher = getServletContext().getRequestDispatcher("/index.jsp"); dispatcher.include(request, response); 回答1: getServletContext() returns a ServletContext object, which has a method called getRequestDispatcher() . Your line of code is just shorthand for two method calls, and