datatype* pointername;
// or
datatype *pointername;

#include <iostream>
using namespace std;

int main()
{
    int num = 10;     
    int *ptr;   // pointer variable

    ptr = &num;

   cout << "Value of the variable: " << *ptr;

   cout << "\nValue at the address: " << ptr;

   return 0;
}

#include <iostream>
using namespace std;

int main() 
{
    int x = 10, *ptr;

/*ptr = x; // Error because ptr is adress and x is value

*ptr = &x;  // Error because x is adress and ptr is value */

ptr = &x; // valid because &x and ptr are addresses

*ptr = x; // valid because both x and *ptr values 

cout << "Value of *ptr: " << *ptr << endl;
 
cout << "Value of &x: " << &x << endl;
 
cout << "Value of ptr: " << ptr << endl;
 
cout << "Value of x: " << x << endl;
}

#include <iostream>

using namespace std;

int main()
{
    int arr[3] = { 2, 3, 4 }; // arr is an array of size 3
    int* ptr = arr; // syntax for making a pointer point to an array
    cout << ptr << endl; //prints the address of arr[0] beacuse ptr stores the address of the first element of arr
    cout << *ptr << endl; //prints the value of the first element i.e, 2
    
    //Now let us see how can we print the whole array by using the pointer
    for (int i = 0; i < 3; i++){
    
        cout << *(ptr + i) << endl;
        
    }
    
    return 0;
}