An example showing GNU `realloc`

realloc_example.c

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

int main() {

    // allocating memory for 6 integers (total = 6 * 4 = 24 bytes)
    int* ptr = malloc(6 * sizeof(int));

    for (int i = 0; i < 6; i++) { /* 6 * 4 = 24 bytes = 24 * 8 = 192 bits */ 
        ptr[i] = INT32_MAX;
    }
    ptr = realloc(ptr, 10 * sizeof(int));

    for (int i = 5; i < 10; i++) {
        ptr[i] = 31;
    }

     
    printf("%lu\n", ptr[0]);

    printf("%lu\n", ptr[10]);
    printf("%lu\n", ptr[11]);

    return 0;
}