An element's attributes can contain useful information for your application, so it's important to be able to get and set them.
.attr() method acts as both a getter and a setter. As a setter,
.attr() can accept either a key and a value, or an object containing one or more key/value pairs.
.attr() as a setter:
.attr() as a getter
"a" ).attr( "href" ); // Returns the href for the first a element in the document