what does scanf do in c++ code example

Example 1: c++ scanf

/* scanf example */
#include <stdio.h>

int main ()
{
  char str [80];
  int i;

  printf ("Enter your family name: ");
  scanf ("%79s",str);  
  printf ("Enter your age: ");
  scanf ("%d",&i);
  printf ("Mr. %s , %d years old.\n",str,i);
  printf ("Enter a hexadecimal number: ");
  scanf ("%x",&i);
  printf ("You have entered %#x (%d).\n",i,i);
  
  return 0;
}

Example 2: c++ how to use scanf

#include <stdio.h>

int main()
{
    int a, b, c;
    printf("Enter the first value:");
    scanf("%d", &a);
    printf("Enter the second value:");
    scanf("%d", &b);
    c = a + b;
    printf("%d + %d = %d\n", a, b, c);
    return 0;
}