Default values for JavaScript variables
Sometimes in JavaScript you want to provide a default value for a variable that can be overridden. That’s super easy to do with the ||
operator.
var elem = document.querySelector('#some-element') || document.createElement('div');
In the example above, elem
will be set to the element on the page with the ID some-element
if such an element exists. If not, an empty div will be created.
I use this all the time in my plugins, where users can pass in options, but don’t have to.
var userOptions = options || {};