In C++ How can I tell the difference between integers and characters?

[lanejared]

Hi...

I am currently learning C++ and I have been asked to make a program which will calculate the interest that would be paid on a deposit of a given size. One of the requirements is that we display an error message when non-integer data is entered.

I however cannot work out how to detect if non-integer data has been entered. If anyone could provide an example of how this problem is solved it would be much appreciated!