Browse questions answered by Jon Skeet

Precedence in Java

Unary postfix increment and decrement operators have more preceedence than relational operators according to precedence table, so why in a expression like this (x++ =10) the...

The operator isn't evaluated first. The ordering is: Evaluate LHS (x++) - the result is the original value of x, then x is incremented Evaluate RHS (10) - the result is 10 Compare the results of the LHS and RHS Here's code to... more 7/11/2017 8:20:46 AM

Derived Class using Parent Method

Why can't i access the age method from either class A or B? I thought because it's a protected method, derived class instances should be able to use it? class Program { ...

Protected means it can be used from code in the derived classes - it doesn't mean it can be used "from the outside" when working with derived classes. The protected modifier can be somewhat tricky, because even a derived class can only... more 7/11/2017 5:46:28 AM

LINQ OrderBy based on row values

Lets say we have two tables Parent "DocumentCodes" and Child "Documents". DocumentCodes table have columns DID,DocumentName,PrintOrder and AscOrDesc Documents table have columns...

The situation is a fairly ugly one, given that two result rows could theoretically be compared which have the same PrintOrder but different AscOrDesc values. It's only the source of the data that's preventing that. I do have a horrible... more 7/10/2017 4:04:49 PM

Generic class and simplified constrains?

Lets say I've got a generic interface IFace<T, U>. The T and U can be constrained in some additional way, but I don't think this is relevant to the problem. I'd like to...

Is this possible, or do I NEED to specify the T and U generic parameters? You need them, I'm afraid. You'll need to have class GenClass<T, TX, TY> where T : IFace<TX, TY> That's assuming you can't create a non-generic... more 7/10/2017 8:10:25 AM

Importance of getting resolved at run time or compile time for .GetType () and Typeof () in c#

I recently read and article about .GetType () and Typeof () methods in c#. Now, I know that both of them return System. Type. That article also indicated that it's important to...

typeof isn't a method - it's an operator. That's how it's resolved at compile time. They don't do the same thing, in that for typeof you need to know the actual type or type parameter1 you want at compile-time, whereas for GetType you... more 7/8/2017 8:50:42 PM

Can you create an initialize method for DLL?

I need to create a service, but the service needs to be in a already existing Class Library file and also the new service needs to start running after the Class Library is...

No, class libraries don't support initialization like this. Note that the library wouldn't even be loaded until it's first used anyway. You could write a type initializer for some appropriate type, and make that start the service - but... more 7/7/2017 7:48:56 AM

StringBuilder and string equality check

I am trying this sample of code and OpTest when System.Console.WriteLine(s == t); it returns false. Can somebody explain this? public static void OpTest<T>(T s, T t) where...

Your generic method will basically be performing a reference equality check - and the values of s1 and s2 refer to different but equal strings. You can show this more easily like this: string x = "test"; string y = new... more 7/7/2017 7:26:08 AM

Remove last character from dictionary<string, dictionary<string, string>> using C#

I have Dictionary<string, Dictionary<string, string>> My inner dictionary has the following data { "1": { "message-Code1": " 0", "msg-Number-Pos11":...

Basically you should create new "inner" dictionaries. That's easy to do though: var replacedOuter = outerDictionary.ToDictionary( outerKey => outerKey, // Outer key stays the same outerValue => outerValue.ToDictionary( ... more 7/6/2017 7:01:12 AM

can not resolve symbol 'from' Error in Android Studio

can not resolve symbol 'from' in LayoutInflater inflater = new LayoutInflater.from(parent.getContext()); this is my complete class: package ir.sangram.sangram.chat; import...

You're calling LayoutInflater.from as if you were calling a constructor: LayoutInflater inflater = new LayoutInflater.from(parent.getContext()); That's a mixture of constructor-call syntax (new) and method call syntax (.from). It would... more 7/6/2017 6:47:27 AM

Get a list of duplicates from list based on properties comparison

I have a List<Demo> public class Demo { public Demo() { } public int Id { get; set; } public string Name { get; set; } public string Title { get;...

It sounds like all you're missing is a SelectMany call. Currently you're creating all the appropriate groups and filtering down to groups with more than one entry - but if you want a single flat list, you need to flatten those groups back... more 7/6/2017 6:44:29 AM