Learn all about the jQuery function .attr().
.attr() method gets the attribute value for only the first element in the matched set. To get the value for each element individually, use a looping construct such as jQuery’s
.attr() method to get the value of an element’s attribute has two main benefits:
- Convenience: It can be called directly on a jQuery object and chained to other jQuery methods.
- Cross-browser consistency: The values of some attributes are reported inconsistently across browsers, and even across versions of a single browser. The
.attr()method reduces such inconsistencies.
Note: Attribute values are strings with the exception of a few attributes such as value and tabindex.
As of jQuery 1.6, the
.attr() method returns
undefined for attributes that have not been set. To retrieve and change DOM properties such as the
disabled state of form elements, use the .prop() method.
Attributes vs. Properties
The difference between attributes and properties can be important in specific situations. Before jQuery 1.6, the
.attr() method sometimes took property values into account when retrieving some attributes, which could cause inconsistent behavior. As of jQuery 1.6, the
.prop() method provides a way to explicitly retrieve property values, while
.attr() retrieves attributes.
defaultSelected should be retrieved and set with the
.prop() method. Prior to jQuery 1.6, these properties were retrievable with the
.attr() method, but this was not within the scope of
attr. These do not have corresponding attributes and are only properties.
Concerning boolean attributes, consider a DOM element defined by the HTML markup
According to the W3C forms specification, the
checked attribute is a boolean attribute, which means the corresponding property is true if the attribute is present at all—even if, for example, the attribute has no value or is set to empty string value or even "false". This is true of all boolean attributes.
Nevertheless, the most important concept to remember about the
checked attribute is that it does not correspond to the
checked property. The attribute actually corresponds to the
defaultChecked property and should be used only to set the initial value of the checkbox. The
checked attribute value does not change with the state of the checkbox, while the
checked property does. Therefore, the cross-browser-compatible way to determine if a checkbox is checked is to use the property:
if ( elem.checked )
if ( $( elem ).prop( "checked" ) )
if ( $( elem ).is( ":checked" ) )
The same is true for other dynamic attributes, such as