JavaScript & jQuery and the use of periods

Question

I am confused when to use the period before the class names when referencing them. In this example why does the first use of the \'active-slide\' class use a period beforehand w

Answer 1

The . character is a selector. It allows you to select ALL DOM elements with that ('active-slide') class.

The jQuery syntax $('') uses selectors to return jQuery wrapped elements.

When you are adding/removing classes, you are not using a selector. You are literally removing a classname which is actually 'active-slide' (no .)

Answer 2

$('.active-slide') is using jQuery's element selector. (add|remove)Class('active-slide'); is modifying the element.