Question

How can I use information from array that will be passed from function?

 #include <stdio.h>

 double get_number(double[]);

 main {

 double x, z[100];
 char m;

 do { 
 x = get_number[z];
 printf("More numbers?");
 scanf (" %c", &m);

      }
 while ((m == 'Y')||(m == 'y'))
}


double get_number(double arr[])
{
    printf ("Please enter number :   ?");
    scanf("%d", &arr);
    return arr;
}

For example
when user press couple times Y and filled array with two or three numbers.
How can I operate with those numbers? count them or just show them.

Answer 1

Use a for() loop.

for (int i = 0; i < array_size; i++) {
     printf ("Number at index %d: %f", i, arr[i]);
}

Of course, you need to know the size beforehand. And don’t use scanf() with an array like that, why not have:

double get_input ()
{
    double number = 0;

    printf ("Please enter number: ");
    scanf ("%d", &number);

    return number;
}

Define your array length to be something fixed:

#define ARRAY_SIZE 1024

if you need more than that, increase the value or consider using a list structure.

Hope this helps

EDIT

If you want to have a sum, for example, you need to first initialize the array:

double array[ARRAY_SIZE];
for (int i = 0; i < ARRAY_SIZE; i++) array[i] = 0;

Then you get the input:

char input;
int counter = 0;
do {
    if (counter > ARRAY_SIZE) break; // dont cause a segmentation fault

    scanf ("%c", &input);
    double number = get_input();
    array[counter] = number;

} while (input == 'Y' || input == 'y');

Then when thats done, just go through the array and sum it up:

int sum = 0;
for (int i = 0; i < ARRAY_SIZE; i++) {
    sum += array[i];
}