I’m new to Java and very confused. I have a large dataset of length 4 int[] and I want to count the number of times that each particular combination of 4 integers occurs. This is very similar to counting word frequencies in a document. I want to create a Map<int[], double> that maps each int[] … Read more
Is there a way to make this method generic so I can return a string, bool, int, or double? Right now, it’s returning a string, but if it’s able find “true” or “false” as the configuration value, I’d like to return a bool for example. public static string ConfigSetting(string settingName) { return ConfigurationManager.AppSettings[settingName]; } 7 … Read more
Closed. This question needs to be more focused. It is not currently accepting answers. Closed 8 years ago. Locked. This question and its answers are locked because the question is off-topic but has historical significance. It is not currently accepting new answers or interactions. I mostly use Java and generics are relatively new. I keep … Read more
The title is kind of obscure. What I want to know is if this is possible: string typeName = <read type name from somwhere>; Type myType = Type.GetType(typeName); MyGenericClass<myType> myGenericClass = new MyGenericClass<myType>(); Obviously, MyGenericClass is described as: public class MyGenericClass<T> Right now, the compiler complains that ‘The type or namespace ‘myType’ could not be … Read more
I have a json string, which I should deSerialize to the following class class Data <T> { int found; Class<T> hits } How do I do it? This is the usual way mapper.readValue(jsonString, Data.class); But how do I mention what T stands for? 10 Answers 10
I am trying to create a generic extension that uses ‘TryParse’ to check if a string is a given type: public static bool Is<T>(this string input) { T notUsed; return T.TryParse(input, out notUsed); } this won’t compile as it cannot resolve symbol ‘TryParse’ As I understand, ‘TryParse’ is not part of any interface. Is this … Read more
In Java, I’d like to have something as: class Clazz<T> { static void doIt(T object) { // … } } But I get Cannot make a static reference to the non-static type T I don’t understand generics beyond the basic uses and thus can’t make much sense of that. It doesn’t help that I wasn’t … Read more
I’m getting deeper into generics and now have a situation I need help with. I get a compile error on the ‘Derived’ class below as shown in the subject title. I see many other posts similar to this one but I’m not seeing the relationship. Can someone tell me how to resolve this? using System; … Read more
When writing xml documentation you can use <see cref=”something”>something</see>, which works of course. But how do you reference a class or a method with generic types? public class FancyClass<T> { public string FancyMethod<K>(T value) { return “something fancy”; } } If I was going to write xml documentation somewhere, how would I reference the fancy … Read more
This question already has answers here: How to check if an object is nullable? (14 answers) Closed 9 years ago. In order to check if a Type ( propertyType ) is nullable, I’m using: bool isNullable = “Nullable`1”.Equals(propertyType.Name) Is there some way that avoid using magic strings ? 2 Answers 2
