static-classes

I've been reading that static methods, static classes, and singletons are evil when you try to implement unit testing in your project. When following the TDD paradigm, should I just forget that they ever existed and never use them again or is it ok to use them sometimes? Phil Sandler Never say never--static classes and methods have their place in your toolbox. That said, if the class you are trying to isolate and test (subject under test or SUT) depends on a static class or method, you will be unable to write a test that isolates the SUT from that static dependency--when your test code runs it

Many times I heard to avoid static classes because they will insert dependencies that will render your code unusable in other projects, and will not allow to unit test it . Let's say we have a typical class DB to access the Data Base, if such class is static we could call it wherever in our code: DB::execQuery(...); but this creates dependencies, so let's make the DB class NOT static, in such case we would have somewhere in our code: $db = new DB(); and then we could call in our code $db->execQuery(...); But now when using the $db inside a function we need each time to first declare it like

Possible Duplicate: What's the difference between an abstract class and a static one? Hello I Would like to know what are all the differences between abstract classes and static classes in C# When do I use what and why? Is it true the abstract class is a class which we cannot create instances of it? Thanks I would like to know what are all the differences between abstract classes and static classes in C#. Don't ask questions like that. I could spend hours listing hundreds of differences, none of which would be relevant to you. What is the most important difference between abstract classes and

I have doubts on static class and static methods. From MSDN I understood that "Static classes and class members are used to create data and functions that can be accessed without creating an instance of the class." So if we don't want to associate a class over an instance , we will make it as static. Is that the only advantage? Can anyone guide me in which real time scenario we go for static class. Some time in classes(not static) I am finding static methods. What advantage/perfomance advantage do static methods give over instance methods in practical. For utility classes they are great. As

I have a general question...when should i be using static classes or static methods?.. I know the idea that static methods can be called without instantiating...and static classes should only be used for static methods?...but are there any performance concerns also with it...and when should they be preferred over instance methods and classes?..If someone could just briefly mention when i should opt for using them and when i should avoid them? Leniel Maccaferri I think the following two links offer a clear answer for what you're looking for. Take a look at them: For static classes: When to Use

I want to serialize a pretty ordinary class, but the catch is it's nested in a static class like this: public static class StaticClass { [Serializable] public class SomeType { ... } } This code: StaticClass.SomeType obj = new StaticClass.SomeType(); XmlSerializer mySerializer = new XmlSerializer(typeof(obj)); Produces this error: StaticClass.SomeType cannot be serialized. Static types cannot be used as parameters or return types. That error seems completely irrelevant; StaticClass.SomeType is not a static type. Is there a way around this? Am I wrong to think this error is dumb? As a pragmatic