Restrict user to input real number only in C++

Question

How can I restrict the user to input real numbers only in C++ program?

Example:

double number; cin >> number;

and it won\'t accept t

Answer 1

I would recommend using this option:

• Firstly, do #include <conio.h>.
• While true:
• Store getch() in a character variable (Will not be displayed on screen).
• Validate the character variable in the previous step.
• If there are any errors, do nothing.
• Else if the character variable is '\r' ('\r\n' normally), break out of the loop.
• Else, output it on the screen.

Answer 2

Unfortunately you cannot avoid it... You can accept a string as input and parse the string (maybe with regex) for correctness.

Answer 3

You can retrieve your data as a std::string then use one of the standard string conversion function to see if the content matches your expectations.

Answer 4

Check out the sscanf function.