If you use $( )
you are using the so called jQuery selector
The selector will select ALL the HTML-Elements of the active HTML-page,
which have attribute you use as an argument.
Thus if you use
$(".article") you are selecting all the HTML-Element's
which have the class="article" set
( you will find 7 Article's)
The jQuery Selector will create an object
which will contain all those selected Elements. AND its children..
Talking in terms of DOM (=Document Object Model )
you select a parent and all its children which are in its tree
Here is the how the Document Object Model view looks like for
+ - - - - - - + - - - - - -+
+ - + - + + - - - - - + - - - - - - +
| | | | |
4 5 8 165 166
link link div script script
+ - - - + - - - + - + - + - - - + - - - + - - - +
| | | | | | |
10 32 54 76 98 120 142
div div div div div div div < .article
+- - - - - - - + - - - - - - - - +
+ - - - - + - - - -+ + - - - - - + - - - - -+
| | | | | |
78 81 84 89 90 94
div div div div div div
+ - - - + - - - +
The numbers in the Diagram
represent the line-number in the index.HTML file.
So to get to the articles we follow the path
html -> 7-body -> 8-div
(we landed at the PARENT of ALL the Articles)
Those Articles are the CHILDREN to this PARENT.
And the CHILDREN between themselves are SIBLINGS.
And ALL these CHILDREN are carrying the Class article.
In this Diagram i have
put the current Class on the 4th Article...
this would happen if you clicked on the 4th-Article
at wich point you have this article at your fingers via
<select all 7 Elements with Class "article" & remove the _attribute_ **class=current** from all those Elements.
<select all 7 Elements with Class "description" & hide those Elements.
<select the Element you just clicked-on, usingthis
as the way to identify this Element, _add the Class_ attribute "current", which via the _style.CSS_ file will cause the change of color via the **.current** CSS-object,
but from now on if we use the jQuery Selection with the argument '.current'
like $('.current') , we know that we have selected 1 Article-Element, with ALL its CHILDREN
<select the'_clicked-on_ Article and ALL its Elements, and from this _collection of Elements_, choose the Element with the _Class_ "description" set, and _show_ that Element and all its Children.
<select all 7 Elements with the _Class_ "description" and _show_ them...you will see all 7 Articles with their description shown.
<select the current Article and ALL it member Elements
step 1 , hide the Article-line using the ".item" Class as sub-selection
step 2 , show the Children Elements of the Parent with Class "description"
news reader compilation == http://www.codecademy.com/forum_questions/5488c6049376766b1b00056e