You can var fooonly declare if it foois a legal identifier.
$(this)is the result of calling a function with a name $with an argument this, so it is not legal in a declaration.
Also, you should not overwrite this- it will cause big head scratches in the future!
If you need a local variable to hold the jQuery version this, then the general convention is:
var $this = $(this);
var $span = $this.find('span');
( , ) $ , jQuery, DOM.
( ) :
var jqobj = $(myobj)
myobj jQuery.