Reading numbers from a text file to an array in user defined function in C

Question

I'm having trouble scanning values from a text file, I've never really used file i/o before and I'm still very shaky with user-defined functions so I'm almost positive that the error is in the first function, I don't know how to fix it however, I'm pretty new at programming so please bear with me.

my code so far is

  #include <stdio.h>
  #include <stdlib.h>

int read_temps(void)
{
    int i;
    int num;
    int fileArray[25];

    FILE *file;
    file=fopen("temperatures.txt", "r");

    if (file == NULL)
    {
        printf("Error Reading File\n");
        exit(0);
    }
    for (i=0; i<25; i++)
    {
    fscanf(file,"%d", &fileArray[i]);
    }

    fclose(file);
    return fileArray[i];

}


int calc_results (int a[], int n)
{
    int i, j, maximum, minimum, average,sum;
    float avg;

printf ("Temperature conditions on October 26th, 2015:\n");
 printf("Time  Temperature in Degrees F \n");

   for(i = 0; i<25;i++)
    {
    printf("%d\t%d\n", i, a[i]);

        if(maximum < a[i])
            maximum = a[i];
        if(minimum > a[i])
            minimum = a[i];

            sum+=a[i];
    }

    printf("Maximum Temperature for the day: %d\n", maximum);
    printf("Minimum Temperature for the day: %d\n", minimum);

    avg=(float)sum/25;
    printf("Average Temperature for the day: %f\n", avg);

    return 0;
}


int main ()
{
    int average,i;

    int temp[25];
        for (i=0;i<25;i++)
        temp[i]= read_temps(); //calling user function for file input

calc_results(temp,i); //calling user function

return 0;
}

the program is supposed to read the values from the .txt file in read_temps, calculate the max, min, and average value in calc_results. It does all this and compiles, but it doesnt read the values correctly. The .txt file contains numbers like 87, 65, 92 and when I run my program the output is the same large number like 19863578 repeated for almost all the values, expect for max, min and avg. I don't know what to do :(

these are the values on the textfil

the output should be

    Temperature Conditions on October 9, 2015: 
    Time of Day     Temperature in degrees F 
    0               85
    1               80
    2               97
    3               90
    4               73
    ........
    25              68

Questions seeking debugging help ("why isn't this code working?") must include the desired behavior, a specific problem or error and the shortest code necessary to reproduce it in the question itself. Questions without a clear problem statement are not useful to other readers. See: How to create a Minimal, Complete, and Verifiable example. — too honest for this site
– too honest for this site, Commented Oct 28, 2015 at 17:27
do you have a fixed pattern of number in every line? if yes then what is that? cos it is important. — XOR-Manik
– XOR-Manik, Commented Oct 28, 2015 at 17:29

Raghu Srikanth Reddy · Accepted Answer · 2015-10-28 17:29:27Z

1

One mistake in your code is that You are calling

for (i=0;i<25;i++)
temp[i]= read_temps();

in your main function. And performing

for (i=0; i<25; i++)
    {
    fscanf(file,"%d", &fileArray[i]);
    }

in your read_temps function which will iterate 25 times all the time and return you the garbage value after the last integer in the file always.

answered Oct 28, 2015 at 17:29

Raghu Srikanth Reddy

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2 Comments

mly128 Over a year ago

How would you properly write it though?

Aram Gevorgyan Over a year ago

mly128 you can look my answer

Aram Gevorgyan · Accepted Answer · 2015-10-28 18:24:16Z

0

It's because you return fileArray[i]; after for loop, when i = 25, and there is no such value in array

write instead:

    int* read_temps(void)
{
    int i;
    int num;
    int fileArray[25];

    FILE *file;
    file=fopen("temperatures.txt", "r");

    if (file == NULL)
    {
        printf("Error Reading File\n");
        exit(0);
    }
    for (i=0; i<25; i++)
    {
    fscanf(file,"%d", &fileArray[i]);
    }

    fclose(file);
    return fileArray;

}

and

int* temp;
temp = read_temps();

edited Oct 28, 2015 at 18:24

answered Oct 28, 2015 at 17:30

Aram Gevorgyan

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