how does const cast work c++ code example

Example: C++ const_cast

// const_cast
#include <iostream>
using namespace std;

void print (char * str)
{
  cout << str << '\n';
}

int main () {
  const char * c = "sample text";
  print ( const_cast< char *>(c) );
  return 0;
}


// const_cast
#include <iostream> 
using namespace std; 

int fun(int* ptr) 
{ 
	return (*ptr + 10); 
} 

int main(void) 
{ 
	const int val = 10; 
	const int *ptr = &val; 
	int *ptr1 = const_cast<int *>(ptr); 
	cout << fun(ptr1); 
	return 0; 
}