C/C++ Help
 
Forums: » Register « |  User CP |  Games |  Calendar |  Members |  FAQs |  Sitemap |  Support | 
 
User Name:
Password:
Remember me
 
Go Back   Dev Articles Community Forums > Programming > C/C++ Help
Reload this Page

Why was it able to pass through?

Discuss Why was it able to pass through? in the C/C++ Help forum on Dev Articles.
Why was it able to pass through? C/C++ Help forum discussing building and maintaining applications in C/C++. Find out why these languages are the foundation on which other languages are built.

Reply
Add This Thread To:
  Del.icio.us   Digg   Google   Spurl   Blink   Furl   Simpy   Y! MyWeb 
« Previous Thread | Next Thread »  
Thread Tools Search this Thread Display Modes
 
Unread Dev Articles Community Forums Sponsor:
  #1  
Old January 19th, 2006, 09:34 PM
devshaikh11 devshaikh11 is offline
Registered User
Dev Articles Newbie (0 - 499 posts)
  
Join Date: Apr 2005
Posts: 7 devshaikh11 User rank is Just a Lowly Private (1 - 20 Reputation Level) 
Time spent in forums: 57 m 39 sec
Reputation Power: 0
Send a message via ICQ to devshaikh11
Question Why was it able to pass through?
Code:
#include <iostream>
#include <cctype>
using namespace std;

int main()
{
	cout << "Enter a line of input:\n";
	char next;
	
	do
	{
		cin.get(next);
		cout << next;
	} while ((! isdigit(next)) && (next != '\n'));
	cout << "<END OF OUTPUT";
	return 0;
}


My input: I'll see you at 10:30 AM.
The Output: I'll see you at 1<End OF OUTPUT

My question is, why didn't the code prevent the digit 1 from being displayed? Why was it able to pass through? How would you track this code?
Reply With Quote
  #2  
Old January 19th, 2006, 10:35 PM
destin destin is offline
Registered User
Dev Articles Newbie (0 - 499 posts)
  
Join Date: Jan 2006
Posts: 18 destin User rank is Just a Lowly Private (1 - 20 Reputation Level) 
Time spent in forums: 1 Day 9 h 6 m 19 sec
Reputation Power: 0
Send a message via AIM to destin
This happens because you are doing cin.get(next);, and then checking after. So you've already stored and printed the character.

What you could do to fis this, is just switch cout << next; and cin.get(next);
Comments on this post
Itsacon agrees: Don't forget to put a cin.get(next); before the loop though.
Reply With Quote
  #3  
Old January 20th, 2006, 10:16 AM
Itsacon's Avatar
Itsacon Itsacon is offline
Command Line Warrior
Click here for more information
 
Join Date: Aug 2004
Location: Sector ZZ9 Plural Z Alpha
Posts: 997 Itsacon User rank is Lance Corporal (50 - 100 Reputation Level)Itsacon User rank is Lance Corporal (50 - 100 Reputation Level)Itsacon User rank is Lance Corporal (50 - 100 Reputation Level)  Folding Points: 906075 Folding Title: Super Ultimate Folder - Level 2Folding Points: 906075 Folding Title: Super Ultimate Folder - Level 2Folding Points: 906075 Folding Title: Super Ultimate Folder - Level 2Folding Points: 906075 Folding Title: Super Ultimate Folder - Level 2Folding Points: 906075 Folding Title: Super Ultimate Folder - Level 2Folding Points: 906075 Folding Title: Super Ultimate Folder - Level 2Folding Points: 906075 Folding Title: Super Ultimate Folder - Level 2
Time spent in forums: 6 Days 14 h 26 m 27 sec
Reputation Power: 5
Send a message via ICQ to Itsacon
Even nicer, and based on my sick use of for() loops for everything (really, it's the greatest function in C).

cpp Code:
Original - cpp Code 
  1. #include <iostream>
  2. #include <cctype>
  3. using namespace std;
  4.  
  5. int main()
  6. {
  7.     char next;
  8.  
  9.     cout << "Enter a line of input:\n";
  10.  
  11.     for(cin.get(next); ((! isdigit(next)) && (next != '\n')); cin.get(next))
  12.         cout << next;
  13.  
  14.     cout << "<END OF OUTPUT";
  15.     return 0;
  16. }
__________________
This is my code. Is it not nifty?

"The biggest problem encountered while trying to design a system that was completely foolproof, was, that people tended to underestimate the ingenuity of complete fools."
---Douglas Adams

Join the Itsacon fanclub!    
Zero Tolerance: Spammers banned so far: 280
Reply With Quote
  #4  
Old January 20th, 2006, 10:17 AM
devshaikh11 devshaikh11 is offline
Registered User
Dev Articles Newbie (0 - 499 posts)
  
Join Date: Apr 2005
Posts: 7 devshaikh11 User rank is Just a Lowly Private (1 - 20 Reputation Level) 
Time spent in forums: 57 m 39 sec
Reputation Power: 0
Send a message via ICQ to devshaikh11
Quote:
Originally Posted by destin
This happens because you are doing cin.get(next);, and then checking after. So you've already stored and printed the character.

What you could do to fis this, is just switch cout << next; and cin.get(next);


thanks destin. I get it now.
Reply With Quote
Reply

Viewing: Dev Articles Community Forums > Programming > C/C++ Help > Why was it able to pass through?

« Previous Thread | Next Thread »

Thread Tools  Search this Thread 
Search this Thread:

Advanced Search
Display Modes  Rate This Thread 
Linear Mode Linear Mode
Rate This Thread:


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
View Your Warnings | New Posts | Latest News | Latest Threads | Shoutbox
Forum Jump


Forums: » Register « |  User CP |  Games |  Calendar |  Members |  FAQs |  Sitemap |  Support | 
  
 





© 2003-2008 by Developer Shed. All rights reserved. DS Cluster 3 hosted by Hostway. 
Stay green...Green IT