How can you validate integer input in C ?

Validating Integer Input in C

To create a program that ensures user input is an integer, one must address the challenge of input validation. Unlike the atoi() function, which is limited to single-digit inputs, an alternative approach is necessary when dealing with multi-digit integer inputs.

As demonstrated in the provided code snippet, one can employ a while loop to repeatedly prompt the user for input until a valid integer is entered. However, the loop's implementation requires a mechanism for checking input validity.

Here's where the cin.fail() method comes into play. When cin encounters non-numeric input, it sets the failbit indicator. By checking if this bit is set using if (!cin), one can determine whether the input is invalid.

Upon detecting an invalid input, the program should:

1. Use cin.clear() to reset the failbit.
2. Employ cin.ignore() to discard the invalid input from the stream.
3. Prompt the user to enter a valid integer again.

This process ensures that the program only accepts valid integer inputs from the user.

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