change all data-item

by Akram kamal

HTML

<div data-item="1">abc</div>
<div data-item="3">abc</div>
<div data-item="1">abc</div>
<div data-item="7">abc</div>
<div data-item="2">abc</div>
<div data-item="5">abc</div>
<div data-item="1">abc</div>

CSS

.red{
    background-color:red;
}

JavaScript

$(function(){
var $v = 1;
    $('[data-item="'+$v+'"]').addClass('red');
});