Browse questions answered by Jon Skeet

Why won't this 'if' statement run in a while loop without something else also happening in the while loop?

I'm having a problem where an if statement is only running if there is something else happening before it in the while loop. Here is the code I want to use: public void load()...

If it makes a difference, the code I've shown above is running in a separate thread. And that's the problem. You're relying on a value set by one thread to be visible in another - and there's no such guarantee without memory barriers... more 7/11/2015 10:28:45 AM

Why can't object of nested class be used as a parameter of supertype constructor?

I have code like the following: class A { final Object data; A(Object _data) { data = _data; } class B extends A { B() { super(new C()); } ...

With a simple nested class, it would be fine. However, you're creating an inner class of B, which means you're implicitly passing a reference to an instance of B - which would be this in this case, and you can't use this before super(...)... more 7/10/2015 3:29:58 PM

rounding up negative floating literal java

Why does -0.5 when being passed on the Math.round results to 0? and 0.5 when being passed also results to 1? shouldn't it be that when you pass -0.5 to Math.round() should also...

Math.round(double) is documented as: Returns the closest long to the argument, with ties rounding to positive infinity. So -0.5 is rounding up (towards positive infinite) instead of down towards negative infinity. It's behaving... more 7/10/2015 3:27:39 PM

C# `foreach` behaviour — Clarification?

I've read Eric's article here about foreach enumeration and about the different scenarios where foreach can work In order to prevent the old C# version to do boxing , the C# team...

MyEnumerator does not has the required public methods Yes it does - or rather, it would if Current were public. All that's required is that it has: A public, readable Current property A public MoveNext() method with no type... more 7/10/2015 2:10:54 PM

type cast rule in java

So known fact: (byte)1 ^ (byte)1 results in an int (per the spec). Can someone explain to me why the following is possible without explicit cast (from int to byte)? byte myByte...

This: (byte)1 ^ (byte)1 is a constant expression (JLS 15.28), which is known to be in the range of byte. You can therefore implicitly convert it to byte in an assignment context (JLS 5.2): In addition, if the expression is a... more 7/10/2015 2:05:21 PM

Format date with timezone in angularjs

Using angularjs 1.2.26 i cant format my date input to the desired timezone, here's an example: http://plnkr.co/edit/CxCqoR3Awcl1NFrCZYjx?p=preview {{'2015-07-10T12:37:08Z' | date...

There are two problems: The time zone support looks like it was introduced post-1.2.26 The time zone support doesn't take an arbitrary TZDB ID. From the docs for v1.4.1: Timezone to be used for formatting. It understands UTC/GMT and... more 7/10/2015 1:55:01 PM

Why does ObservableCollection<T> implement INotifyPropertyChanged?

In .NET 4.0, there isn't a single property defined by ObservableCollection<T> nor does it override any property of its parent or interfaces. So why does...

Both Count and Item[] changes are notified. Here's a sample (using C# 6 just for the string interpolation): using System; using System.ComponentModel; using System.Collections.ObjectModel; class Test { static void Main(string[]... more 7/10/2015 1:47:56 PM

Performance in linq to entity queries between linq and lambda?

I have a doubt in a query that it's a little bit slow and i want to know what's best for performance. Let's present this first example: var result = from tableA in...

It would be exactly the same. Query expressions are basically converted to the non-query-expression equivalent. You'd need to use select new { tableA, tableB } or something similar anyway, so that you could use both variables after... more 7/10/2015 1:41:58 PM

GitHub for Windows does not see changes in repository

I have created a repository using GitHub for Windows (GfW) and added 3 commits and synced using aforementioned. Commits were visible on GitHub webpage and in my app. Then my...

Well, there are four repositories involved here: Your github one Your local clone of your github project Your brother's github fork Your brother's local clone of his fork I haven't used GfW myself for a little while, but I suspect that... more 7/10/2015 10:53:59 AM

Getting a count of unique strings from a List<string[]> into a dictionary

I want to input a List<string[]> and The output is a dictionary where the keys are unique strings used for an index and the values is an array of floats with each position...

It sounds like you could use something like: var dictionary = doc .SelectMany(array => array) .Distinct() .ToDictionary(word => word, word => doc.Select(array => array.Count(x => x == word)) ... more 7/10/2015 10:14:10 AM