static-methods

问题 I have a problem that I haven\'t been able to find anywhere on the web (it may be there, but I can\'t find it, heh). I have a spreadsheet with 13 columns of data. Each of the column contains variations of a parameter that needs to go into an overall test case. All of them differ, like E: 101% 105% 110% 120% J: Upper S Upside L Downside B Premium V I have seen several solutions to the combination issue which uses nested loops. I\'d like to steer clear of 13 nested loops (but this is my best

问题 Why does ReSharper complain when a method can become static, but is not? Is it because only one instance of a static method is created (on the type) and thus save on performance? 回答1: I find that comment very useful as it points out two important things: It makes me ask myself if the method in question should actually be part of the type or not. Since it doesn't use any instance data, you should at least consider if it could be moved to its own type. Is it an integral part of the type, or is

问题 I\'m trying to write a python class which uses a decorator function that needs information of the instance state. This is working as intended, but if I explicitly make the decorator a staticmetod, I get the following error: Traceback (most recent call last): File \"tford.py\", line 1, in <module> class TFord(object): File \"tford.py\", line 14, in TFord @ensure_black TypeError: \'staticmethod\' object is not callable Why? Here is the code: class TFord(object): def __init__(self, color): self

问题 When is it considered poor practice to use the static keyword in Java on method signatures? If a method performs a function based upon some arguments, and does not require access to fields that are not static, then wouldn\'t you always want these types of methods to be static? 回答1: One reason why you may not want it to be static is to allow it to be overridden in a subclass. In other words, the behaviour may not depend on the data within the object, but on the exact type of the object. For

问题 I have concept of static variables but what are the benefits of static methods in a class. I have worked on some projects but I did not make a method static. Whenever I need to call a method of a class, I create an object of that class and call the desired method. Q: Static variable in a method holds it\'s value even when method is executed but accessible only in its containing method but what is the best definition of static method? Q: Is calling the static method without creating object of

问题 My question is relating to the performance characteristics of static methods vs instance methods and their scalability. Assume for this scenario that all class definitions are in a single assembly and that multiple discrete pointer types are required. Consider: public sealed class InstanceClass { public int DoOperation1(string input) { // Some operation. } public int DoOperation2(string input) { // Some operation. } // … more instance methods. } public static class StaticClass { public static

问题 I have a class that must have some static methods. Inside these static methods I need to call the method getClass() to make the following call: public static void startMusic() { URL songPath = getClass().getClassLoader().getResource(\"background.midi\"); } However Eclipse tells me: Cannot make a static reference to the non-static method getClass() from the type Object What is the appropriate way to fix this compile time error? 回答1: Just use TheClassName.class instead of getClass() . 回答2: As

问题 The question is in Java why can\'t I define an abstract static method? for example abstract class foo { abstract void bar( ); // <-- this is ok abstract static void bar2(); //<-- this isn\'t why? } 回答1: Because "abstract" means: "Implements no functionality", and "static" means: "There is functionality even if you don't have an object instance". And that's a logical contradiction. 回答2: Poor language design. It would be much more effective to call directly a static abstract method than

问题 When I attempt to use a static method from within the body of the class, and define the static method using the built-in staticmethod function as a decorator, like this: class Klass(object): @staticmethod # use as decorator def _stat_func(): return 42 _ANS = _stat_func() # call the staticmethod def method(self): ret = Klass._stat_func() + Klass._ANS return ret I get the following error: Traceback (most recent call last):<br> File \"call_staticmethod.py\", line 1, in <module> class Klass

问题 In a non-static method I could use this.GetType() and it would return the Type . How can I get the same Type in a static method? Of course, I can\'t just write typeof(ThisTypeName) because ThisTypeName is known only in runtime. Thanks! 回答1: If you're looking for a 1 liner that is equivalent to this.GetType() for static methods, try the following. Type t = MethodBase.GetCurrentMethod().DeclaringType Although this is likely much more expensive than just using typeof(TheTypeName) . 回答2: There's