Arrays vs pointers in C

arr_vs_ptr.c

#include <stdio.h>

void print_sizeof(char* ptr) {
  printf("The passed variable is %u bytes large\n", (unsigned int)sizeof(ptr));
}

int main() {
  char arr[] = "Hello World!";
  char* ptr = "Hello World!";

  printf("arr is %u bytes large\n", (unsigned int)sizeof(arr));
  printf("ptr is %u bytes large\n", (unsigned int)sizeof(ptr));

  printf("when passed to a function, an array decays into a pointer.\n");
  print_sizeof(arr);
  print_sizeof(ptr);

  return 0;
}