Browse questions answered by Jon Skeet

Why incrementing int primitive in while loop does not loop forever

I have a following code sample int i = 1; while(i != 0) { i++; } I was expecting this to run in an infinite loop but it didn't. Then when I printed the value...

I was expecting this to run in an infinite loop but it didn't. No, it wouldn't. Eventually the value will become 0 again. In particular, it will logically execute like this: 1 2 3 ... 2,147,483,646 2,147,483,647 -2,147,483,648 //... more 1/13/2014 6:59:32 AM

Double to int rounding normal way from .5

I'm making calculation and for that I'm using the following expression: Player.targetx = (int) (((e.getX() - Frame.x)/(Screen.myWidth/World.worldWidth))-8); For example: if...

Casting to int always truncates towards 0. To round, you can use Math.round() instead. However, that always rounds halves up: class Test { public static void main(String[] args) { System.out.println(Math.round(-7.7)); // -8 ... more 1/12/2014 4:34:43 PM

C# Dynamics: Convert.ChangeType versus Cast

Could someone explain why casting a dynamic object as a class returns that class while using Convert.ChangeType returns a dynamic object, particularly at runtime? For instance: ...

At execution time, there's no such thing as dynamic really. However, the call to Convert.ChangeType is providing a dynamic value as an argument. Any method call using a dynamic argument is treated as having a return value of dynamic,... more 1/12/2014 1:43:27 PM

Why is tinyxml's FirstAttribute() return null in simple function?

Running on: Linux Mint 16, QtCreator 3.0.0 with Qt 5.2.0. tinyXML last version. XML working with: <users> <user> <username>testadmin</username> ...

Your XML doesn't have any attributes. It has text within elements, but no attributes. If your XML had something like: <user name="foo" /> then it would give you an attribute. And you could have multiple attributes of... more 1/11/2014 11:23:25 PM

How to set position of MediaElement?

I have this button: private void Answer1_Click(object sender, Windows.UI.Xaml.RoutedEventArgs e) { MediaElement1.Play(); } The problem is that if I click it and then...

Yes, just set the Position property: MediaElement1.Position = TimeSpan.Zero; MediaElement1.Play(); more 1/11/2014 11:22:16 PM

How do i get the cropped integer number

I'm trying to calculate the age based on the DOB. Int32 DOB = 19900427; Int32 current = 20140111; Int32 result = current - dob; Now i just need to display the starting 2 digit...

Don't do it that way. Just don't. You can't get a useful age representation by subtracting one value from another - you'll find that the difference between two people who were born a day apart can differ massively based on exactly when... more 1/11/2014 5:46:48 PM

How to store convert date time in int?

I need to store DateTime in int. So I tried below codes Int64 n = Int64.Parse(DateTime.Today.ToString("dd-MM-yyyy")); or Int64...

Just use DateTime.Ticks instead - there's absolutely no reason to start converting to and from strings here. long ticks = DateTime.Today.Ticks; // Later in the code when you need a DateTime again DateTime dateTime = new... more 1/11/2014 1:12:26 PM

NullReferenceException was unhandled in C# Timer TweetSharp

I am working on a twitter project that lets user to auto-tweet to the mentioned tweets using C#. I am using TweetSharp with C#. The problem is, when I try to refresh the form_load...

I've come across exactly this problem in the last week. I strongly suspect that it is related to access tokens expiring or other errors: I've regularly seen this occur after my program has been active for 5 minutes (of polling every 20... more 1/11/2014 1:04:00 PM

enclosingInstance.newMermberClass(args) in java effective java text

In effective java second edition, the author says, It is possible, although rare, to establish the association manually using the expression enclosingInstance.new...

It means "create a new instance of MemberClass, using enclosingInstance as the reference for the new instance". An inner class has an implicit reference to its enclosing class - normally if you just call new MemberClass() within an... more 1/11/2014 11:06:52 AM

DateTime.Parse changes format

I'll try to illustrate an example: var dateNow = DateTime.Now.ToString("dd/MM/yyyy HH:mm:ss"); produces: 10/01/2014 21:50:34 var dateNowParse =...

How to parse the date, and keep formatting You need to keep the format alongside the DateTime if you want to. A DateTime does not have any concept of being in a particular format. The value of the DateTime returned by Parse isn't... more 1/10/2014 8:01:08 PM