javascript - What is the difference between $("selection") and $("selection", $(this)) -

javascript - What is the difference between $("selection") and $("selection", $(this)) -

i have seen utilize of $(this) , understand within function, have seen in selector well, fail understand when or if valuable. here 2 examples can utilize , work, doing valuable...

here added $(this) in selectors

(function($) { $(".deliver").on('mouseenter',function(){ $(this).css({'width':'600px'}); $(".form_jquery",$(this)).fadein(1000).css({'display':'block'}); $(".componentheading",$(this)).css({'display':'none'}); }); ...

here original script

(function($) { $(".deliver").on('mouseenter',function(){ $(this).css({'width':'600px'}); $(".form_jquery").fadein(1000).css({'display':'block'}); $(".componentheading").css({'display':'none'}); });

i have kept know standard utilize of (this) in both , noting using in anonymous function in case factors in.

$(".componentheading",$(this))

only searches .componentheading elements under current $(this) element (in particular case it's .deliver entered mouse) whereas

$(".componentheading")

searches them in whole document.

http://api.jquery.com/jquery/#jquery1

javascript jquery anonymous-function