plumb crazy

[bpayne111]

	
using System;

namespace DELETEONEDAY
{
class Class1
{
	[sTAThread]
	static void Main(string[] args)
	{
		char[] userInput = new char[4];

	Console.WriteLine("Please input 4 numbers. (after each number press the enter key).");

	for(int x = 0; x <=3; x++)
	{
		userInput[x] = (char)Console.Read();
	}
	for(int x = 0; x <=3; x++)
	{
		Console.WriteLine(userInput[x]);
	}
	}
}
}

 

this code looks simple enough... you may wonder why i posted it.

 

I run this code expecting to input 4 chars then displaying them on the screen...

 

It loops 4 times as expected but only prompts me for input twice??????

here's an example of what happens when i run it.

 

<user input: 1>

<user input:2>

 

program displays

 

1

 

 

2

 

 

the 2nd and 3rd Console.Read statements are run by the program but it does not pause for me to input the value.

i'm stumped.

(if you are wondering why i have made such a simple program it's because this is actually a java program i must write for school. the results seemed so bizzare to me, i swithced over to C# and ran the same code again only to have the same results. we aren't required to use the loops but only because we haven't 'learned' them yet... i thought i was good to go but.. maybe i'm wrong)

 

******edit***** problem sovled

 

ok so it works if i hit enter after i enter all 4 char... that's cool cuz it works...

but why is the user prompted twice if enter is pressed after each input char?

 

(i'm happy it's fixed but confused as to what happens when the user screws up)

 

brandon

Edited January 26, 2004 by bpayne111

[NK2000]

i would suggest: use ReadLine

 

 

string input = Console.ReadLine();

 

after that you can parse the number:

 

 

 

private bool ParseToInt(string text, out int number)
{
 number = 0;

 try
 {
   number = Int32.Parse(text);
 }
 catch
 {
   return false;
 }

 return true;
}

 

if you dont like that out and want to return an int value then this is also ok but you dont know if the parsing failed.. so number = 0 would be the alternative if the parsing failes

[bpayne111]

the question at hand is why is the output from that code the way it is.

 

thanks for the help though

brandon

[PlausiblyDamp]

The problem is .Read() takes the next character from the input - including The CRLF pair.

e.g. If you type 1 then 2

the buffer will be

userInput[0] = '1' //byte 49

userInput[1] = //byte 13

userInput[2] = //byte 10

userInput[3] = '2' //byte 50.

 

as NK2000 suggested use readline as this handles the CRLF automatically.

[bpayne111]

aha thank you .... i forgot about the lf part...

thanks

brandon

[NK2000]

i forgot someting which could matter

 

always trim the userinput to go sure there are no hidden/invisible chars at end of line