Old task: Read pairs (a number and string) from the keyboard, and then display them on the screen. New task: Read the same pairs from the keyboard and store them in a HashMap. Any empty input string signifies the end of data entry. The numbers can be repeated, but not the strings. The entered data must not be lost! Then the program should display the contents of the HashMap on the screen, each pair on a new line.
Functionality is not enough!