[Solved] how can I define limit of an array by the quantity of numbers put in scanf?

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This example allows the user to enter numbers “indefinitely” without the need for prompting how many to enter. Of course, your computer only has so much RAM, so there is a limit, but not a practical limit. Essentially, you need to choose an initial size, then allocate more space dynamically when that size is reached.

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

#define INITIAL_SIZE 10

void printArray(const int* myArray, size_t numsEntered)
{
    for (size_t i=0; i<numsEntered; i++)
    {
        printf("myArray[%zu] = %d\n", i, myArray[i]);
    }
}

int main(void)
{
    size_t arraySize = INITIAL_SIZE;
    size_t numsEnteredSoFar = 0;
    int* myArray = malloc(sizeof(*myArray) * arraySize);  // initially make room for 10
    if (myArray == NULL) exit(-1);  // whoops, malloc failed, handle this error how you want

    while(1)
    {
        int curEntry;
        printf("enter a number, or 'q' to quit: ");
        if (scanf("%d", &curEntry) == 1)
        {
            // store in the array, increment number of entries
            myArray[numsEnteredSoFar++] = curEntry;

            // here you can check for positives and negatives, or
            // wait to do that at the end. The point of this example
            // is to show how to dynamically increase memory allocation
            // during runtime.

            if (numsEnteredSoFar == arraySize)
            {
                puts("Array limit reached, reallocing");
                // we've reached our limit, need to allocate more memory to continue.
                // The expansion strategy is up to you, I'll just continue to add
                // INITIAL_SIZE
                arraySize += INITIAL_SIZE;
                int* temp = realloc(myArray, arraySize * sizeof(*myArray));
                if (temp == NULL)
                {
                    // uh oh, out of memory, handle this error as you want. I'll just
                    // print an error and bomb out
                    fprintf(stderr, "out of memory\n");
                    exit(-1);
                }
                else
                {
                    // realloc succeeded, we can now safely assign temp to our main array
                    myArray = temp;
                }
            }
        }
        else
        {
            // the user entered 'q' (or anything else that didn't match an int), we're done
            break;
        }
    }

    // print the array just to show it worked. Instead, here you can
    // loop through and do your comparisons for positive and negative,
    // or you can continue to track that after each entry as you've
    // shown in your code
    printArray(myArray, numsEnteredSoFar);

    free(myArray);
    return 0;
}

Demo

1

solved how can I define limit of an array by the quantity of numbers put in scanf?