My loop within loop won't work

Ayreon · 03-18-2009, 10:11 AM

I made a loop which reads from some lines a file.
It works fine but now I want the loop within another loop.

Once I remove the now commented loop in this code, it doen't show the printf anymore:

Code:

    //for(i = 0; j < 10; i++) 
       //{   
       for (j = 0; j < N_points - 2 ; j++)
           {
           fgets(string, 512, input);
           sscanf(string, "%lf %lf", &spectrum[i].wavelength[j], &spectrum[i].intensity[j]);
           
           
           printf ("\n %d\t%g    \t%g", j, spectrum[i].wavelength[j], spectrum[i].intensity[j]);
           }
       //}

Anyone know why?

vart · 03-18-2009, 10:13 AM

i = 0; j < 10; i++)

**laserlight** · 03-18-2009, 10:13 AM

Use a debugger. Maybe N_points <= 2, so the loop never runs at all.

EDIT:
Oh wait, once you remove the comments it does not work... haha, ok, vart is probably on the right track here.

Ayreon · 03-18-2009, 10:44 AM

Thanks vart, that was the problem

. Needed a fresh pair of eyes apparently.

03-18-2009, 10:11 AM	#1
Ayreon Astrophysics student Join Date: Mar 2009 Location: Netherlands Posts: 70	My loop within loop won't work I made a loop which reads from some lines a file. It works fine but now I want the loop within another loop. Once I remove the now commented loop in this code, it doen't show the printf anymore: Code: //for(i = 0; j < 10; i++) //{ for (j = 0; j < N_points - 2 ; j++) { fgets(string, 512, input); sscanf(string, "%lf %lf", &spectrum[i].wavelength[j], &spectrum[i].intensity[j]); printf ("\n %d\t%g \t%g", j, spectrum[i].wavelength[j], spectrum[i].intensity[j]); } //} Anyone know why? __________________ Nothing to see here, move along...
Ayreon is offline

03-18-2009, 10:13 AM	#2
vart CSharpener Join Date: Oct 2006 Posts: 5,556	i = 0; j < 10; i++) __________________ If I have eight hours for cutting wood, I spend six sharpening my axe.
vart is offline

03-18-2009, 10:13 AM	#3
laserlight C++ Witch Join Date: Oct 2003 Location: Singapore Posts: 12,459	Use a debugger. Maybe N_points <= 2, so the loop never runs at all. EDIT: Oh wait, once you remove the comments it does not work... haha, ok, vart is probably on the right track here. __________________ C + C++ Compiler: MinGW port of GCC Build + Version Control System: SCons + Bazaar Look up a C/C++ Reference and learn How To Ask Questions The Smart Way
laserlight is offline

03-18-2009, 10:44 AM	#4
Ayreon Astrophysics student Join Date: Mar 2009 Location: Netherlands Posts: 70	Thanks vart, that was the problem . Needed a fresh pair of eyes apparently. __________________ Nothing to see here, move along...
Ayreon is offline

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
loop the loop - feeling foolish	estos	C Programming	2	04-07-2007 02:45 AM
A mini-compilier I made stuck in an infinite loop (lots of code)	dan06	C++ Programming	1	10-27-2006 01:21 PM
The Bludstayne Open Works License	frenchfry164	A Brief History of Cprogramming.com	8	11-26-2003 11:05 AM
fopen();	GanglyLamb	C Programming	8	11-03-2002 12:39 PM
for loop or while loop	slamit93	C++ Programming	3	05-07-2002 04:13 AM