Quick reference on C pointers

pointers.c

/**
 * @file pointers
 * @brief A hello world example.
 *
 * This a file with some pointers. Documentation can be generated with doxygen.
 */

#include <stdio.h>

/**
 * Calculate a=a+b, b=a*b.
 *
 * @param a An int.
 * @param b Another int.
 */
static void add_and_multiply(int *a, int *b) {
    int oldA = *a;
    *a = *a + *b;
    *b = oldA * *b;
}

void function_of_array(char *an_array) {
    an_array[0] = '42';
}

int main()
{
    char some_array[1];
    function_of_array(some_array);
  
    int a = 7;
    int b = -5;
  
    add_and_multiply(&a, &b);
    printf("a=%d b=%d\n", a, b);
}