method-call

问题 Closed . This question is opinion-based. It is not currently accepting answers. Want to improve this question? Update the question so it can be answered with facts and citations by editing this post. Closed 9 days ago . Improve this question i experienced this questions in a during the job interview, but i cant answered it and i cant find the answer after. They asked me 'Why methods return just one kind of parameter in normal conditions in C#? (ref-out is extra way to return multiple

问题 I would like to extract the element name, and not the specific value, from a list used for the choices argument in selectInput() from R Shiny. The selectInput function looks like this: # ... selectInput("xvar", "What is the predictor variable?", choices = list("MPG" = "mpg", "Cylinders" = "cyl", "Engine Displacement" = "disp", "Horse Power" = "hp", "Gears" = "gear"), # ... In my server.R code I would like to use, for example, "Cylinders" and not "cyl" as an axis label. For example (using

问题 I would like to extract the element name, and not the specific value, from a list used for the choices argument in selectInput() from R Shiny. The selectInput function looks like this: # ... selectInput("xvar", "What is the predictor variable?", choices = list("MPG" = "mpg", "Cylinders" = "cyl", "Engine Displacement" = "disp", "Horse Power" = "hp", "Gears" = "gear"), # ... In my server.R code I would like to use, for example, "Cylinders" and not "cyl" as an axis label. For example (using

问题 Dealing with another SO question, I was wondering if the code below has an undefined behavior: if (str.equals(str = getAnotherString())) { // [...] } I tend to think the str reference from which the equals() call is made is evaluated before the further str assignment passed as argument. Is there a source about it? 回答1: This is clearly specified in the JLS Section 15.12.4: At run time, method invocation requires five steps. First, a target reference may be computed. Second, the argument

问题 Dealing with another SO question, I was wondering if the code below has an undefined behavior: if (str.equals(str = getAnotherString())) { // [...] } I tend to think the str reference from which the equals() call is made is evaluated before the further str assignment passed as argument. Is there a source about it? 回答1: This is clearly specified in the JLS Section 15.12.4: At run time, method invocation requires five steps. First, a target reference may be computed. Second, the argument

问题 Here's the problem - I know function by name (and that function has already been loaded form an external script), but I don't have an actual function object avail for me to call. Normally I would call eval(function_name + "(arg1, arg2)"), but in my case I need to pass an object to it, not a string. Simple example: var div = document.getElementById('myDiv') var func = "function_name" -- this function expects a DOM element passed, not id How do I execute this function? Thanks! Andrey 回答1: You

问题 In my business, we have a few teams that work on very simple macros. I'm trying to make them all readable to each other and in somewhat of a similar format, so new joiners can start working on the data. I mention simple macros, because no one will be using Subs with arguments - most are derived from Macro Recorder anyway Half of the teams use: Sub button() Call sub1() Call sub2() Call sub3() Call sub4() End Sub And the other half use Sub button() Application.Run("sub1") Application.Run("sub2"

问题 is it possible? Object obj=null; obj.someMethod(); someMethod{/*some code here*/} 回答1: You can call a static method on a null pointer. The pointer will naturally be completely ignored in a static method call, but it's still a case when something that (without looking at the class definition) seemingly should cause a NullPointerException runs just fine. class FooObject { public static void saySomething() { System.out.println("Hi there!"); } } class Main { public static void main(String[] args)

问题 Out of curiosity: how does the CLR dispatch virtual method calls to interface members to the correct implementation? I know about the VTable that the CLR maintains for each type with method slots for each method, and the fact that for each interface it has an additional list of method slots that point to the associated interface method implementations. But I don't understand the following: how does the CLR efficiently determine which interface method slot list to pick from the type's VTable?

问题 I like to call the method in thread with arguments and return some value here example class Program { static void Main() { Thread FirstThread = new Thread(new ThreadStart(Fun1)); Thread SecondThread = new Thread(new ThreadStart(Fun2)); FirstThread.Start(); SecondThread.Start(); } public static void Fun1() { for (int i = 1; i <= 1000; i++) { Console.WriteLine("Fun1 writes:{0}", i); } } public static void Fun2() { for (int i = 1000; i >= 6; i--) { Console.WriteLine("Fun2 writes:{0}", i); } } }