Revision 3a04a1ba-4d37-481a-9048-a6405c5bb481 - Stack Overflow

Yes, you can do that:

 $('.obj').get(0).key = 'value';

or

 $('.obj').get(0)['key'] = 'value'

Though it's better to use [`.data()`](http://api.jquery.com/data):

 $('.obj').data('key', 'value');

---

### Tips

**1.** You can chain multiple calls, like this:

 $('.obj').css('color', 'red').data('key', 'value');

**2.** You can pass an object to `.css()`:

 $('.obj').css({
 'width': 100,
 'height': 100
 });

**3.** If you don't change other CSS properties, you can use `.width()`and `.height()` to set and get an element's width:

### HTML

 <div id='box'></div>

### CSS

 #box {
 width: 200px;
 height: 100px;
 }

### JavaScript

 var $box = $('#box');
 // 200x100
 alert( $box.width() + 'x' + $box.height() );

**4.** You may have noticed in the previous example that I saved a reference to `$('#box')` in a variable. There are some cases when you can't use chaining, like this:

 var $box = $('#box');
 setTimeout(function() {
 $box.animate({ 'width': 100 }, 100);
 }, 1000);
 setTimeout(function() {
 $box.animate({ 'height': 200 }, 100);
 }, 1000);

If you have to do that, **always** save a reference to the element – that's called caching. Otherwise jQuery would have to search for it multiple times.