Adding attribute in jQuery

Question

How can I add an attribute into specific HTML tags in jQuery?

For example, like this simple HTML:

<input id="someid" />

Then adding an attribute disabled="true" like this:

<input id="someid" disabled="true" />

Answer 1

Set the width attribute of an image:

$("button").click(function(){
  $("img").attr("width","500");
});