I can read values from separate lines: int age; double salary; cin >> age; cin >> salary; works whether the user types both on one line or presses Enter between them. If the user types 25 and presses Enter, then 50000.50 and presses Enter, both reads succeed.
The first cin >> age consumes 25. The second cin >> salary skips the newline and reads 50000.50. You can prompt before each input: cout << "Age: "; cin >> age; cout << "Salary: "; cin >> salary; makes the program interactive.
Newlines between values do not cause problems for numeric types.