C++ Read Int From File to Array

01-11-2013

Hey everyone!

Then i have a simple programme that's supposed to read upwardly to 50 values from a .txt file, store the values in an assortment, and impress the values to the user. However, when I run the program, it just outputs nothing to the user..but a blank infinite, i don't run across any values.... i created the .txt file and saved information technology into "My Documents" on my computer so I'k pretty sure the program knows how to access it....maybe there'southward some other fault in my code that i'm not catching?

If anyone would similar to help, I would greatly appreciate your assist!!
Give thanks Y'all

And here's my code:

Code:

/*Written by: Kalpana Chinnappan Date: Jan 17, 2013 Homework ane */     #include <stdio.h>      int main (void)  {     int nums[50];   //upwardly to fifty element int assortment     FILE *fp1;      //file pointer     int i;      //******************  code starts here ***************     for(i=0;i<50;i++)   //initialize array with 0         nums[i]=0;     i=0;        //clean up and initialize LCV     if ((fp1=fopen("votes.txt","r"))==NULL)     {     printf("votes.txt failed to open\n");     render 1;     }     else         while((fscanf(fp1,"%d",&nums[i]))!=EOF) //scanf and cheque EOF         {             printf("nums[%d] is %d\n",i,nums[i]);             i++;         }       return 0;  }

01-11-2013

Other then the fact that:

Lawmaking:

                      //******************  lawmaking starts here ***************     for(i=0;i<50;i++)   //initialize array with 0         nums[i]=0;

Can easily exist done at initialization:

Lawmaking:

int nums[l] = {0};

In that location is cipher wrong with the code and every bit long as votes.txt is in the current directory the program is run from, should work fine. What are the contents of votes.txt?
Should be something like:

Code:

230 2398 34988 30489 9488 8598 34893 48984 34989 489 49848 58958 985

01-11-2013

See, working fine for me:

Code:

$ cat test.c #include <stdio.h>    int chief(void) {     int nums[l] = {0};     int i = 0;     FILE * fp;      if (fp = fopen("votes.txt", "r")) {         while (fscanf(fp, "%d", &nums[i]) != EOF) {             ++i;         }         fclose(fp);     }      for (--i; i >= 0; --i)         printf("num[%d] = %d\n", i, nums[i]);      render 0; } $ true cat votes.txt  234 34 344908 3498 340823 402348 437 43297 43298 293847 348973 498724 28934  9349873 38947 34987 293847 293847347 48 $ ./a.out  num[18] = 48 num[17] = 293847347 num[16] = 293847 num[15] = 34987 num[14] = 38947 num[thirteen] = 9349873 num[12] = 28934 num[eleven] = 498724 num[ten] = 348973 num[nine] = 293847 num[8] = 43298 num[vii] = 43297 num[half dozen] = 437 num[v] = 402348 num[4] = 340823 num[3] = 3498 num[two] = 344908 num[ane] = 34 num[0] = 234

You should really throw a i < 50 cheque in the while () condition likewise.

01-12-2013

Ohh ok, and so I can just supplant that whole "for" loop with:

Lawmaking:

                          int nums[50] = {0};

I dont know if i'll do it, but it should piece of work both ways, thanks for showing me a simpler way

and actually, the contents are:

Code:

                                                  0 3 3 2 3 0 4 two iv iv two 0 0 0 4 2 3 3 3 iii 0 ii 0 0 1 1 1 ii iii 4 4 0 3 4 0 0 iii three iv 4 4 4 0

OHHHH i just saw your reply......peradventure that's my problem, cause I didn't include the i<fifty in my while loop....thanks soooo much for helping out!! lemme go and see if it works now!!!

01-12-2013

Like I said there is nothing in the code that is causing it to not work. How are you executing information technology? Is it but running a quick popup window and then disappears?

Regarding your logic, if each numerical value represents a candidate and then why not practise something like this:

Code:

#include <stdio.h>  int main(void) {     int candidates[5] = {0};     int i;     FILE * fp;      /* note this has no 50 size limit every bit earlier.. */     if (fp = fopen("votes.txt", "r")) {         while (fscanf(fp, "%d", &i) != EOF) {             /* invalid vote (out of range */             if (i < 0 || i > v) {                 fprintf(stderr, "Invalid Candidate: %d!\n", i);                 keep;             }              /* otherwise we got a valid vote, count it */             ++candidates[i];         }         fclose(fp);     }      for (i = 0; i < 5; ++i)          printf("Candidate #%d had %d votes\n", i, candidates[i]);      return 0; }

01-12-2013

ok let me see if the code that u gave me works...and it only gives me the black running window with a bare space at where the values are supposed to be printed, then:

"Procedure returned 0 (0x0) execution fourth dimension : 0.031 s
Press any central to continue."

idk whats wrong!!

01-12-2013

Read and Answer my questions, so maybe you will figure it out ?

01-12-2013

Welcome to the forum, kal!

Your file is not being opened. Your program volition only piece of work if the data file is moved or copied into the same directory that it is located in.

Not "My Documents". Must be the very same directory. You lot aren't seeing the error message, because the console window is closing before yous can see the message.

01-12-2013

@nonpuz

Ok so you asked how I was executing it--I'm using codeblocks, just building and running the program. Ok, and then I used the lawmaking you only gave me (the candidate ane) and information technology's finally outputting some results!!! Thanks!! The only problem is that I need the up to 50 size limit to still be at that place (because what if I take more than fifty numbers?), merely i'll try and figure that out on my ain. Besides, the output that i get is:

Candidate #0 had 0 votes
Candidate #ane had 0 votes
Candidate #2 had 0 votes
Candidate #3 had 0 votes
Candidate #iv had 0 votes
Candidate #v had 0 votes
Candidate #6 had 0 votes
Candidate #7 had 0 votes
Candidate #8 had 0 votes
Candidate #nine had 0 votes

Procedure returned 0 (0x0) execution fourth dimension : 0.031 south
Press whatever key to continue.

In my instance, there are but v candidates, so ignore the output stuff for "candidate 5" to "candidate nine". But look at the candidate vote count until "candidate four". Somehow it says that all 5 candidates got 0 votes...how do I get the program to really impress out the number of votes each candidate has? delight give me slight hints, I'll try to figure nearly of it out on my ain, It wouldnt be fair if u did my homework for me haha :P

01-12-2013

@Adak
Ohhhhh!! Wow deceit imagine why I couldnt effigy that out earlier haha! Thanks!!

01-12-2013

Ok so that tells me that its not reading anything from your file. Either the file is non in the directory or it is not readable or fscanf is failing. Put a "printf()" call right after the "fopen" call that just says "openned file successfully". Execute and run and see if it outputs opened file successfully. If information technology does, then move on and put a printf() call in the while loop just before the ++candididate[i] line;

C++ Read Int From File to Array

reading from file and storing the values in an array!! HELP PLEASE!! :O

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