Exercise: In memory counter
- Create an application that has a button called 'Increment' and shows a number.
- Every time the button is clicked the number increases by 1.
- Implement it in a single HTML file without a 'script' tag.
- Add another button called 'Decrement'.
- When the user clicks that button the counter is decremented.
- Still have this in a single HTML file without a 'script' tag.
- Change the application now moving everything to a controller.
- Both the initialization and the code of increment and decrement.
- Disallow negative numbers: If the user clicks on 'decrement' while the counter
- is at 0, display a message in a 'div' element that this operation is not allowed.