Trouble understanding what this code does

[NotoriousProgramer]

Hello there,
I am doing a program to check if a number is a palindrome or not.i have trouble understanding what the following does.it would be a great help if you could answer.thanks in advance.

cout<<"Enter any Number:";
cin>>n;
num=n;
do
{
d=n%10;
rev=(rev*10)+d;
n=n/10;
}while(n!=0);

[keskiverto]

The answer is probably "42", because
1. The code sets value for variable 'num' that is not used anywhere.
2. The initial value of variable 'rev' is not known

cout << "Enter any Number:";
cin >> n;
num = n;
do
{
  d = n % 10;
  rev = (rev*10) + d;
  n = n / 10;
} while ( n!=0 );

While you don't understand all of the code, you must understand some of it.

1. Start by explaining each statement that you do know.

2. Let me give you a test input: "24". n==24 at start.
Evaluate the code statement by statement and keep record of the values of all variables.