C# Unhadled.Exception: System.NullReferenceException Visual Studio

Asked Feb 04 '15 at 00:19

Active Feb 04 '15 at 00:35

Viewed 54 times

I have a problem with Console.WriteLine()

When I try to print mathematical signs (+ , *) and other symbols (@, #, \, ~ , ;, ", '), I receive Unhadled.Exception: System.NullReferenceException.

If I insert a letter from the alphabet or a number everything is alright.

string expression = Console.ReadLine();

        foreach (char symbol in expression)
        {
            Console.WriteLine(symbol);
        }

Screenshot of NullReferenceException https://i.stack.imgur.com/buDRZ.png

Proof Image https://i.stack.imgur.com/IAL7y.jpg

edited Feb 04 '15 at 00:35

asked Feb 04 '15 at 00:19

zdzdz

it means that your symbol variable does not contain anything – ako Feb 04 '15 at 00:25
So what's line 15 of Program.cs? – Dour High Arch Feb 04 '15 at 00:28
2

The code you've provided doesn't display the behavior you describe. – Preston Guillot Feb 04 '15 at 00:29
Line 15 is: foreach (char symbol in expression) This is the whole code. Nothing else. – zdzdz Feb 04 '15 at 00:30
use this:char [] input=console.readline().tochararray();then print array – ako Feb 04 '15 at 00:30
1

https://dotnetfiddle.net/1BrKPf <- no error. – Blorgbeard Feb 04 '15 at 00:32
But I want it my way. It should be working. Why do I receive exception? – zdzdz Feb 04 '15 at 00:36
Well that's certainly interesting. No idea what's going on. Voted to reopen. – Blorgbeard Feb 04 '15 at 00:36
Could it be the system locale? Mine is Japan. – zdzdz Feb 04 '15 at 00:40
I can't think of any reason that would make a difference, but maybe? Can you set a breakpoint and check whether `expression` is null after `ReadLine`? – Blorgbeard Feb 04 '15 at 00:43
I tried setting `CultureInfo.DefaultThreadCurrentCulture` to ja-JP and still don't see the behavior that's being described from the debugger. – Preston Guillot Feb 04 '15 at 00:49
According to [the documentation](https://msdn.microsoft.com/en-us/library/system.console.readline(v=vs.110).aspx) `Console.ReadLine()` can return `null` if Ctrl+Z (EOF) is pressed – Ryan Emerle Feb 04 '15 at 00:56
I tried too. It's not the locale. I checked and is never . If I insert ++++ for example, it's value never changes. The funny thing is this happens only with Ctrl+F5. If I try with F5 everything is alright. – zdzdz Feb 04 '15 at 01:03
I solved my problem. I restored a previous System Backup. Everything is back to normal. – zdzdz Feb 05 '15 at 11:32

C# Unhadled.Exception: System.NullReferenceException Visual Studio

0 Answers0