Thread: How do I increase the size of an array?

Cannot be done. What you can do is to use dynamic memory allocation with say, malloc, instead.

You haven't provided enough information on what you are trying to achieve.

The simplest approach is to do what you've done: change the 3 to a 5 and recompile.

If you want the size to be changeable at run time (eg the size is input by the user) use malloc()

Code:

#include <stdio.h>
#include <stdlib.h>    /*  declares malloc() and free()   */

int main()
{
    int i, size;
    int *test;      /*   note this is a pointer, not an array */
    printf("Enter size : ");
    scanf("%d", &size);

    test = malloc(size*sizeof(*test));     /*  dynamically allocate memory for size ints */

     /*  Use test as if it is an array  */

    for (i = 0; i < size; ++i)
         test[i] = i;

    /*  other stuff using test as an array  */

   for (i = 0; i < size; ++i)
       printf("%d\n", test[i]);
   
   free(test);     /*  when we no longer need the memory supplied by malloc(), remember to free() it */

   return 0;
}