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JavaScript Introduction to jQuery Hello, jQuery! Filtering Matched Elements

Danish Saleem
Danish Saleem
7,965 Points

need help in implementing and understanding not

I am trying to implement .not() function in the index.html(see below) <!DOCTYPE html> <html> <head> </head> <body> <ul> <li>Thing 1</li> <li>Thing 2</li> <li>Thing 3</li> </ul> <script src="http://code.jquery.com/jquery-3.2.1.min.js" integrity="sha256-hwg4gsxgFZhOsEEamdOYGBf13FyQuiTwlAQgxVSNgt4=" crossorigin="anonymous"></script> <script src="app.js"></script> </body> </html>

with following jQuery

$('li').on('click',function() { $(this).not(":even").text("clicked"); });

so that only the odd number 'li' get the clicked text , but somehow it is not working , need help as what i am doing wrong here

1 Answer

Steven Parker
Steven Parker
229,920 Points

When you apply .not(":even") to a set of elements, it will select every element in the set with an odd-numbered ("not even") index. Note that the index numbers are relative to the set itself and have nothing to do with the element positions relative to their container!

Now $(this) is an element set with only one item in it, so that element has an index number of 0 (even). And .not(":even") will always generate an empty result set when applied to a set with a single item.

If you still want to do what you were attempting another way, this came to mind:

  // test if this item's index within its parent is odd:
  if ($(this).parent().children().index(this) & 1) {

Also, when posting code, always the instructions for code formatting in the Markdown Cheatsheet pop-up below the "Add an Answer" area. :arrow_heading_down:   Or watch this video on code formatting.