Fix "Call to a member function format() on null" Joomla error with an example from the Admin Panel.
Learn how to create a vertical line in CSS using the border-left property, with an example.
"Learn how to call functions in Python with an example: def add_numbers(a, b): return a + b; print(add_numbers(1, 2))"
Javascript callback functions allow easy reuse of code. Learn how to create one with an example.