question: reading numbers into an array

I'm having a heck of a time with this problem. I want this short program to read the array of numbers, and tell me how many numbers are in the array. What I'm getting besides the memory addresses, is a list of the numbers which I don't need. Just how many numbers it counts in the array. this line: printf("%d\n", outputList[numFound]); isn't required I was just using it to test to see what I'm getting. Any ideas? thank you.

Code:

#include <stdio.h>

#define MAX_SIZE 100

int getinput( double outputList[]); // function prototype

int main (void) {


int array[] = {3,4,5,67,5,43,2,2,3,4,5,5,6,5,4,2,3,5};

getinput(array); // function call


return 0;

} // end main


int getinput( double outputList[]) { // function definition

	int numFound = 0;	// counter 
	
	  for (numFound = 0; numFound < ; numFound++)
                 {

	     printf("%d\n", outputList[numFound]);
	 }
	 return numFound;

} // end function getinput

after a quick glance what is your condition in the for loop?
"for (numFound = 0; numFound < ; numFound++)"

and your function is looking for a double array, and your sending an int array

Code:

#include <stdio.h>

#define MAX_SIZE 100    /* donno what this is for */

int main (void) {

        int array[] = {3,4,5,67,5,43,2,2,3,4,5,5,6,5,4,2,3,5};

        printf("%d\n", sizeof(array)/sizeof(*array));

return 0;

} // end main

this method cannot be used in another function though, since your not really sending the array, just a pointer to it.

Code:

printf("%d\n", outputList[numFound]);

You cannot print double value with the %d format

okie I see what your saying about the int array and reading a double that explains why I kept getting that warning thank you!.

As for what the condition the for loop is checking for I've tried everything I could think of.

numFound < outputList[numfound]
numFound < outputList[MAX_SIZE]
numFound < outputList[]

none of which works. the MAX_SIZE definition is condition on the longest possible number array that I will be presented with.

And what about value suggected by the sl4nted?

I like sl4nted's solution, however my problem is a bit more difficult since I'm using the function to actually read a list of numbers from a txt file and pass the number of elements into the main and the actual values that were read. This array will be read from a txt file I think I have the reading part figured out. I redid the code and it is doing what I want now. (printing out the elements, counting how many elements there are and passing it to main). I'm going to use fscanf to read the values in the file and pass them to main through the function, is that viable? The problem I'm going to have is I won't have a definite array size when I read the txt file, all I know is it will be 1-100 numbers, so I cannot use my line that declares how big the array is. Any Idea how I can overcome this?

Code:

#include <stdio.h>

// Constants
#define MAX_ARRAY_SIZE 100
 

// Function Prototypes 
 int Getinput(double outPutList[]);

// begin main function
int main(void) { 
 
  // Local Variables

  int numfound = 0;
  double fakeArray[] = {0};

  // begin main work
  numfound = Getinput(fakeArray);
  
  printf("length of list: %d\n", numfound);

 return 0;
 
} // end function main 


 
 int Getinput(double outPutList[]) { // function definition 
 
  // Local Variables
  double a[MAX_ARRAY_SIZE]= {4,7,6,4,23,65,2};
  double inputArraySize = 7;
  int i = 0;
 
  // Begin function work
  for (i = 0; i < inputArraySize; i++) {
    printf("%f\n", a[i]);
  } // end for
  return i;
 
} // end function Getinput

So why not just allocate enough space for 100 numbers ?

I've tried to allocate for 100 numbers, but when I execute it gives me all zero's until the last allocated space is reached so I'll have 4,7,6,4,23,65,2,0,0,0,0,0,0,... until a[99]. that wouldn't really be a problem, however, I have to use this list that is put into main, as the parameters for a few other mathematical functions, like averaging and such.

So why don't you count how many items you read in, and stop looping when you reach that number for the rest of your program?


Quzah.

I'm really mystified now, I thought I had this thing working great and all I would have to do is create a while loop to read numbers from a text file, however, things are screwed up. I have my array in the function, what I want though is the inputArray to pass to fakeArray. I thought I could do that by the line outPutList[i] = inputArray[i]; and that this would pass a copy of outPutList to become fakearray. The program compiles fine, but I get a run-time error. here is what happens.

1. program prints out elements of array inputArray
2. program prints out how many elements are in the array
3. program hits run-time error
4. program prints 0 7 0 0 0 0 0 then closes

Code:

#include <stdio.h>

// Constants
#define MAX_ARRAY_SIZE 100
 

// Function Prototypes 
 int Getinput(double outPutList[]);
void PrintArray( double inputArray[], int inputArraySize);

/////////////////////////////////////////////////////////////////////////////////////
int main(void) { 
 
  // Local Variables

  int numfound = 0;
  double fakeArray[] = {0};
 
  // begin main work

  numfound = Getinput(fakeArray);
  
  printf("length of list: %d\n", numfound);

  PrintArray(fakeArray, numfound);

 return 0;
 
} // end function main 


 int Getinput( double outPutList[]) { // function definition 
 
  // Local Variables
  double  const inputArray[MAX_ARRAY_SIZE] = {4,7,6,4,23,65,2};
  double inputArraySize = 7;
  int i = 0;
 
  // Begin function work
  for (i = 0; i < inputArraySize; i++) {
    printf("%f\n", inputArray[i]);
    outPutList[i] = inputArray[i];  // define what outPutList will be
  } // end for
  return i;
 
} // end function Getinput

// end file 

void PrintArray(double inputArray[], int inputArraySize) { 
 
  // Local Variables
  int i = 0;
 
  // Begin
  for (i = 0; i < inputArraySize; i++) {
    printf("%d\n", inputArray[i]);
  } // end for
 
} // end function PrintArray

Originally Posted by quzah

So why don't you count how many items you read in, and stop looping when you reach that number for the rest of your program?


Quzah.

I'm not sure how to do that.

Code:

prompt user for number
read number into variable

loop while counter is less than variable
    do stuff

Just like that.


Quzah.

Code:

  double fakeArray[] = {0};

This allocates array of 1 element.
Use

Code:

  double fakeArray[100];

to allocate a little bit more.

[edit]
or even better

Code:

  double fakeArray[MAX_ARRAY_SIZE];

also

Code:

  double  const inputArray[MAX_ARRAY_SIZE] = {4,7,6,4,23,65,2};
  double inputArraySize = 7;

better replace with

Code:

double  const inputArray[] = {4,7,6,4,23,65,2};
double inputArraySize = sizeof(inputArray)/sizeof(inputArray[0]);

[/edit]

I've never seen anyone represent the size of an array with a double before...