I know this might sound stupid, but how am I supposed to know when I've finished inputting numbers? I don't see anything saying what A is equal to, so how do I know?

read FAQ.

for C++:

double n;
while (scanf("%lf", &n) != EOF)
{
   ...
}

I have the same question.
What about Java? there's no answer to that in FAQ.

Just catch Exception :D

How to make the EOF? I mean how does it know when the user stopped inputting?

As for C#, you can use (as an example):

string[] inputValues = Console.In.ReadToEnd().Split(new char[] {' ', '\t', '\n', '\r'}, StringSplitOptions.RemoveEmptyEntries);

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Edited by author 02.02.2013 14:58

Edited by author 02.02.2013 14:58

I have same prblm in  c.

I have the same problem with Go. Can someone help me.

For windows command prompt CTRL Z would be interpreted as EOF

For linux terminal Ctrl + d is the EOF character.

You'll know the input has ended when one of the following happens, depending on the method you choose to read in the first place :

InputStreamReader in;
while(in.read() != -1)

BufferedReader in;
while((line = in.readLine()) != null)

You'll know the input has ended when one of the following happens, depending on the method you choose to read in the first place :

InputStreamReader in;
while(in.read() != -1)

BufferedReader in;
while((line = in.readLine()) != null)