I need help

Question

//Write a program that receives a integer, positive three-digit number (number in the range 100-999 inclusive) by the following message

#include <iostream>
using namespace std;

int main() {

cout << "enter a three digit number:" << endl;
int digit1,digit2,digit3,sum;
int num;
digit1 = (num%10),
digit2 = (num/10%10),
digit3 = (num/100),
cout << "the sum is: ";
sum = digit1 + digit2 + digit3 ;
cout << "the sum is" << sum << endl ;
return 0;
}

Answer 1

Add this line to read value for variable <num>:

cin >> num;

Before this line:

digit1 = (num % 10);

(Edit)
For the next time, please be more descriptive with your question. "I need help" didn't describe the problem clearly, other than being ineffective way to communicate.