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JavaScript jQuery Basics (2014) Creating a Mobile Drop Down Menu Perform: Part 3

Dee K
Dee K
17,815 Points
Posted by Dee K
Dee K
17,815 Points

Questions arising from the conditional statement in this video.

The conditional code in this video made me think about browser functionality.

 if ($anchor.parent().hasClass('selected')) {
      $option.prop('selected', true);
  }

How does the web browser intelligently know which page it is on?

I understand this code is essentially saying if the parent element (list item) has a class of selected, set the selected property in $option to true.

But my question is HOW does the browser know which page it is on? We have 6 html docs, yet the browser can understand which page it is on?

Thanks

1 Answer

Joel Bardsley
Joel Bardsley
31,249 Points
Joel Bardsley
Joel Bardsley
31,249 Points

Hi Dee, in this instance there isn't any browser intelligence going on. As you say there's six HTML files - each HTML file has its own unordered list with the 'selected' class assigned, and each HTML file loads the same js file at the bottom of the page. So every time a page loads, the js starts again and looks through the current file for the list item with the 'selected' class.

If there was one unordered list written in a template file that was shared across all six pages, using the current code the js file wouldn't know what page it was on, and additional code would need to be written to retrieve the current url from the address bar as well as adding/removing classes to the list items.

Hopefully I've made it clear enough, if anything needs further clarification please let me know.

Dee K
Dee K
17,815 Points
Dee K
Dee K
17,815 Points

Hello Joel,

Thanks for your reply. From your reply, it seems as if you're saying, it is the "selected" class that determines how the web browser knows what page it is on?