Stefan,
thanks for that help. I actually managed to figure out that I had an
infinite loop after a while and I did it by sticking in a println("what is
happening here ?") statement just inside the opening bcurly bracket of thw
while loop and then when I did that and then executed the program, an
inifinte number of "what is happening here ?" statements in my output. So
that gave me the clue that I didn't increment or adjust the variable that
affected my condition of my while loop.
So I eventually figured that part out. The part that I didnt figure out was
the problem that I had afterwards when my output gave me a value that wasn't
quite right.
But somoene suggested to me that that may be due to using integer arithmetic
rather than double or float arithmetic. So tomorrow I am going to try that
and see if that improves things.
ScreenWriter and KeyboardReader are part of the
TerminalIO.* package that comes along with the Lambert and Osborne book --
Java a Framework for Programming and Problem Solving.
----- Original Message -----
From: "Stefan Carlsson" <[EMAIL PROTECTED]>
To: "JDJList" <[EMAIL PROTECTED]>
Sent: Monday, September 23, 2002 8:39 PM
Subject: [jdjlist] SV: having a problem that I can't understand....
Well... haven't give your calculations any thought
(guess you know what you are doing...), but first
you must increse your variable "i" (like i++) somewhere
within your while -loop, or your will never get out
of that scoop. Also, perhaps you must "flush();" your
ScreenWriter (?). Don't know if it works like the
"OutputSreamWriter" -class ?, which must bee flushed
to print anything (default). Is "ScreenWriter" part
of jdk 1.4 ?
Regards
stefan
-----Ursprungligt meddelande-----
Fr�n: Tim Nicholson [mailto:[EMAIL PROTECTED]]
Skickat: den 22 september 2002 15:52
Till: JDJList
�mne: [jdjlist] having a problem that I can't understand....
Hi,
can somebody please help me ?
I am trying to run the following code :-
----------------------------------------------------------------------------
-------------
import TerminalIO.*;
public class Liebniz {
KeyboardReader reader = new KeyboardReader();
ScreenWriter writer = new ScreenWriter();
int i;
int x;
int numiter;
double valuesofar;
//================================================================
public void run() {
numiter = reader.readInt("Enter number iterations for Pi value: ");
i = 1;
x = 1;
valuesofar = 0;
while (i <= numiter) {
if(i % 2 == 0){
valuesofar = valuesofar - (1 / x);
}
else {
valuesofar = valuesofar + (1 / x);
}
x = x + 2;
}
writer.println("The value so far is: " + valuesofar);
}
//=================================================================
public static void main(String [] args) {
Liebniz tpo = new Liebniz();
tpo.run();
}
}
----------------------------------------------------------------------------
---------------------
And when I execute it, it succeeds in asking me to enter a number of
iterations but then after I have entered in an integer and push enter,
nothing more happens. In other words it only gets as far as
the cursor going onto the next line. But nothing more happens.
So it doesnt display any output to my input.
The cursor just goes to the next line and stops and I have to push the X
button in the top right hand corner of the window to get it to close. What
usually happens is that it runs its output and then says "push any key to
continue " but when I try this program it doesnt do any of that. It just
sits on the next line after I have entered my input and it doesnt display
anything more.
Can someone please help me with this ?
I get no compile errors by the way with this.
The program is also attached as a .java file if that makes things any easier
?
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