Free Pascal Tutorial 21 - Error Handling Try Except

The application used in Tutorials 18, 19, 20 crashes, or comes up with confusing error messages, if a non-number is entered into the calculator.

We can make this situation more user friendly by using an error catching technique.

Using Try - Except can stabilize the program and tell the user what is happening if an error occurs.

The Syntax:

Try
    Statement

Except
     Statement
End;

Code Used in Tutorial 18, 19, 20, and 21: