Write a program that uses while loops to perform the following steps:
a. Prompt the user to input two positive integers. Variables: firstNum and secondNum
(firstNum must be less than secondNum) (use while loop); create a user-defined function
called validateUserInput() to validate the user's input. Use Call-by-Value.
validateUserInput() is a value returning function.

b. Output all odd numbers between firstNum and secondNum. (use while loop); create a
user-defined function called oddNumbers(). Use Call-by-Value. oddNumbers() is a void
function.

c. Output the sum of all even numbers between firstNum and secondNum. (use while
loop); create a user-defined function called sumEvenNumbers(). Use Call-by-Value.
Declare a variable called sumEven in the main() for the sumEvenNumbers().
sumEvenNumbers() is a valuereturning function. Use sumEven to hold a returned value.

d. Output the numbers and their squares between 1 and 10. (use while loop): create a
user-defined function called displaySquareNumbers(). Call-by-Value.
displaySquareNumbers() is a void function.

e. Output the sum of the square of the odd numbers between firstNum and secondNum.
(use while loop); create a user-defined function called sumSqureOddNumbers(). Use
Call-by-Value. Declare a variable called sumSquareOdd in the main(), for the

sumSqureOddNumbers(). sumSqureOddNumbers() is a value returning function. Use
sumSquareOdd to hold a returned value.

f. Output all uppercase letters. (use while loop); create a user-defined function called
displayUppercaseLetters(). Use Call-by-Value. displayUppercaseLetters() is a void
function.