Why use $ (dollar sign) in the name of javascript variables?
Possible Duplicates:
Why would a javascript variable start with a dollar sign?
JQuery : What is the difference between “var test” and “var $test”
What is the difference between this two ways of initializing variables?
var $val = 'something'
OR
var val = 'something'
as I see they are the same thing.
Maybe in this case $ is only the part of name in variable? (it will become a meaningless question in that case:/)
Thanks
The $ in the variable name is only part of the name , but the convention is to use it to start variable names when the variable represents a jQuery object.
var $myHeaderDiv = $('#header');
var myHeaderDiv = document.getElementById('header');
Now later in your code, you know the $myHeaderDiv is already a jQuery object, so you can call jQuery functions:
$myHeaderDiv.fade();
To get from the DOM-variable to the jQuery variable:
var $myHeaderDiv = jQuery(myHeaderDiv); //assign to another variable
jQuery(myHeaderDiv).fade(); //use directly
//or, as the $ is aliased to the jQuery object if you don't specify otherwise:
var $myHeaderDiv = jQuery(myHeaderDiv); //assign
$(myHeaderDiv).fade(); //use
To get from the jQuery variable to the DOM-variable.
var myHeaderDiv = $myHeaderDiv.get(0);
You are correct. $ is a part of the name of the variable.
This is not perl or PHP :)
No real difference..
It is usally used to signify a variable holding a jquery or other javascript framework object, because they can have shorthand $ function..
It is just easier to identify the type of the contents..
链接地址: http://www.djcxy.com/p/94952.html上一篇: $在变量的开头和结尾