The following do-while loop is suppose to ask for the price for a gallon of gas. The price must a positive number. The price can be an integer value or a double value. for example the price can be 3 or 3.0 or 3.5.
To create a robust program, we must do the data validation and as long as the user is entering a negative value or a String, the program must keep asking the user to enter a valid input.
in this program you need to use some of the scanner methods listed here, make sure to use the proper ones: hasNextInt(), hasNextDouble(), hasNextLine(), hasNext(), nextInt(), nextDouble(), nextLine()
Must flush the buffer at the proper locations in the code
