Implement the hex2Dec function in Programming Exercise 16.1 to throw a HexFormatException if the string is not a hex string . Define a custom exception class named HexFormatException. Write a test program that prompts the user to enter a hex number as a string and displays the number in decimal. If the function throws an exception, display "Not a hex number".

C++   You did this way back in Unit 1! But now all of your RomanNumber code is wrapped up in a class, so the "main" program is short and sweet. As before, write a program that accepts entries from the user.   If it's an integer, convert to Roman Number and display. If it's a Roman Number, convert to integer and display. If it's neither, thrown an exception and continue to process The action to take here will be to display an error message If the entry is 0 or O (The digit 0 (zero) or the letter O) exit and state how many conversions were done of each type (integer to Roman and Roman to integer) and how many exceptions were thrown.   As I said, the main program will be short and sweet. Provide your .cpp code and a screen shot of your program in action. Enter twelve conversions - four integer to Roman, four Roman to integer, and two of each in which the input is invalid so that I can see the exceptions. The thirteenth and final entry will be 0 or O.

Design and implement a program that creates an exception classcalled StringTooLongException, designed to be thrown when astring is discovered that has too many characters in it. In the maindriver of the program, read strings from the user until the userenters "DONE". If a string that has too many characters (say 20) isentered, throw the exception. Allow the thrown exception toterminate the program

Write a C++ program that converts 12-hour time (including AM/PM) to 24 hour time. You must define an exception class called InvalidTime wherein if the user enters an out of range time or gibberish characters, your program will throw and catch InvalidTime. Make your class support the following code: TwelveHourTime sevenAM( "7:00 AM" );cout << sevenAM.twentyFourTime( ) << endl;   // prints "07:00"TwelveHourTime eightPM( "8:30 PM" );cout << eightPM.twentyFourTime( ) << endl;  // prints "20:30"try{  TwelveHourTime bad( "asef32422" );  // the previous line should throw an InvalidTime exception} catch( InvalidTime ) {  cout << "caught error as expected" << endl;}