473,511 Members | 14,933 Online
Bytes | Software Development & Data Engineering Community
+ Post

Home Posts Topics Members FAQ

"do while" loop

1 New Member
Hello - I am a brand new at Java and I am having a hard time with a program I have to turn in tomorrow. I can not get the 'Q' option to work and the loop goes on forever. I've tried to go over the tutorials but when I change it from here I then get compiling issues... Can someone explain what I've done wrong?
Expand|Select|Wrap|Line Numbers
  1. import javax.swing.JOptionPane;
  2. public class LloydPage_Assignment5 {
  3.   public static void main (String [] args) {
  4.  
  5. //  Enter Y to vote yes
  6. //  Enter N to vote no
  7. //  Enter Q to quit voting
  8.     int quitVote = 0;
  9.     int yesVote = 0;
  10.     int noVote = 0;
  11.  
  12. //  charAt looks at number in parenthesis, returns char at that location
  13. //    within string (the first character is at location 0)
  14. //    firstChar is going to be 'Y' or 'N' or 'Q' etc.
  15. //  Essentially it is a way to make a string into a char so that you may use string function
  16.  
  17.     String reply1 = JOptionPane.showInputDialog
  18.       (null, "Enter 'Y' to vote yes, 'N' to vote no, or 'Q' to quit voting");
  19.     char userVote = reply1.charAt(0);
  20.  
  21. //  If the user enters Y or y then add 1 to the number of yes votes    
  22.  
  23.      do { 
  24.       yesVote = yesVote + 1;
  25.        reply1 = JOptionPane.showInputDialog
  26.        (null, "Enter 'Y' to vote yes, 'N' to vote no, or 'Q' to quit voting");
  27.     userVote = reply1.charAt(0);
  28.     } while ((userVote == 'Y') || (userVote == 'y'));  
  29.  
  30. //  If the user enters N or n then add 1 to the number of no votes    
  31.  
  32.     do {
  33.       noVote = noVote + 1;
  34.        reply1 = JOptionPane.showInputDialog
  35.        (null, "Enter 'Y' to vote yes, 'N' to vote no, or 'Q' to quit voting");
  36.     userVote = reply1.charAt(0);
  37.     } while ((userVote == 'N') || (userVote == 'n'));
  38.  
  39. //  If the user enters any variable other than Y||y, N||n, Q||q then ignore vote
  40.  
  41.     do {
  42.        reply1 = JOptionPane.showInputDialog
  43.        (null, "Enter 'Y' to vote yes, 'N' to vote no, or 'Q' to quit voting");
  44.     userVote = reply1.charAt(0);
  45.     } while ((userVote != 'Y') || (userVote != 'y') || (userVote != 'N') || (userVote != 'n') || (userVote != 'Q') || (userVote != 'q'));    
  46.  
  47. //  If the user enters Q or q then
  48. //  use a showConfirmDialog box
  49. //  to ask if they really want to quit
  50.  
  51.     do {
  52.       quitVote = JOptionPane.showConfirmDialog
  53.       (null, "Are you sure you wish to Quit?");
  54.     } while ((userVote == 'Q') || (userVote == 'q')); 
  55.  
  56. //  Otherwise the loop ends and the totals must be shown in a
  57. //  showMessageDialog box
  58.  
  59.     do {  
  60.      JOptionPane.showMessageDialog(null, "The total is number of Yes votes is " + yesVote + "\n The total is number of No votes is " + noVote);
  61.     } while (quitVote == JOptionPane.YES_OPTION);
  62.  
  63.   }
  64. }
Sep 23 '08 #1
1 4570
JosAH
11,448 Recognized Expert MVP
Your logic is incorrect; you want to collect Y or N votes until the user wants to
quit; then you want an additional confirmation from the user. If the user really
wants to quit you display the totals and quit. Otherwise you just continue.
Check your text book for the switch() statement and don't be afraid to add a
few simple methods for sub-tasks. Here's a first idea:

Expand|Select|Wrap|Line Numbers
  1. for (char vote= 'A'; !quitVote(vote); ) {
  2.    vote= getVote();
  3.    switch (vote) {
  4.       case 'y': case 'Y': yesVote++; break;
  5.       case 'n': case 'N': noVote++; break;
  6.       case 'q': case 'Q': quitVote++; break;
  7.       default: illegalVote(vote);
  8.    }
  9. }
  10.  
The getVote() and illegalVote() methods handle what they have to handle.
The quitVote() method checks whether or not the user really wants to quit.

kind regards,

Jos
Sep 23 '08 #2

Sign in to post your reply or Sign up for a free account.

Similar topics

6
12203
by: Sybren Stuvel | last post by:
Hi there, Is it possible to use an assignment in a while-loop? I'd like to do something like "loop while there is still something to be read, and if there is, put it in this variable". I've been...
11
2240
by: Wayne Folta | last post by:
Two observations about PEP-315: 1. It's clever, addresses a definite "wart", and is syntactically similar to try/except. But it's syntax seems like an acquired taste to me. 2. It is a very...
6
71934
by: John Pass | last post by:
What is the difference between a While and Do While/Loop repetition structure. If they is no difference (as it seems) why do both exist?
9
1634
by: morpheus | last post by:
Hi Group, When I run this: # include <stdio.h> int main(){ int c=0; while ( (c=getchar()) != EOF && c != ' ' && c != '\t' ) printf("foo"); if (c == '8') putchar(c);
1
1245
aprilmae36
by: aprilmae36 | last post by:
Nice day to all... Here I am again, having another problem with loops... lol... Can you please help me make a while loop program that the output will be like this: 1 121 12321 1234321...
14
19397
by: Jan Schmidt | last post by:
Hi, in a nested do-while-loop structure I would like to "continue" the outer loop. With goto this should be no problem in while-loops. However, for do-while I cannot get it to work (without a...
3
2125
by: archeryguru2000 | last post by:
Hello, I've been stumped for several weeks on this particlar program. At work here, we have 30 machines that we record scrap data on. I take this data and create spreadsheets (boring) that can be...
2
3216
by: recordlovelife | last post by:
So I am trying to display a title, date, and content of a wordpress blog. Word press provides nice drop in functions to get the job done with simple names like "the_title", and the "the_content" But...
1
2286
by: Kerem Gümrükcü | last post by:
Hi All, i am too tired now to find this out by my own, but why does my while loop "while(readline==Console.ReadLine())" needs twice return hit to read the line, after setting...
11
1634
by: cokofreedom | last post by:
First off let me state that I really enjoy using Python. I am a 3rd year student and have been using python for 3 months, (thanks to trac!). I do not consider myself an experienced or clever...
0
7237
marktang
by: marktang | last post by:
ONU (Optical Network Unit) is one of the key components for providing high-speed Internet services. Its primary function is to act as an endpoint device located at the user's premises. However,...
0
7137
by: Hystou | last post by:
Most computers default to English, but sometimes we require a different language, especially when relocating. Forgot to request a specific language before your computer shipped? No problem! You can...
0
7349
Oralloy
by: Oralloy | last post by:
Hello folks, I am unable to find appropriate documentation on the type promotion of bit-fields when using the generalised comparison operator "<=>". The problem is that using the GNU compilers,...
0
7417
jinu1996
by: jinu1996 | last post by:
In today's digital age, having a compelling online presence is paramount for businesses aiming to thrive in a competitive landscape. At the heart of this digital strategy lies an intricately woven...
0
7506
tracyyun
by: tracyyun | last post by:
Dear forum friends, With the development of smart home technology, a variety of wireless communication protocols have appeared on the market, such as Zigbee, Z-Wave, Wi-Fi, Bluetooth, etc. Each...
0
5659
agi2029
by: agi2029 | last post by:
Let's talk about the concept of autonomous AI software engineers and no-code agents. These AIs are designed to manage the entire lifecycle of a software development project—planning, coding, testing,...
1
5063
isladogs
by: isladogs | last post by:
The next Access Europe User Group meeting will be on Wednesday 1 May 2024 starting at 18:00 UK time (6PM UTC+1) and finishing by 19:30 (7.30PM). In this session, we are pleased to welcome a new...
0
3210
by: adsilva | last post by:
A Windows Forms form does not have the event Unload, like VB6. What one acts like?
1
780
muto222
by: muto222 | last post by:
How can i add a mobile payment intergratation into php mysql website.

By using Bytes.com and it's services, you agree to our Privacy Policy and Terms of Use.

To disable or enable advertisements and analytics tracking please visit the manage ads & tracking page.