Question

How can I check if an item is set in localStorage? Currently I am using

if (!(localStorage.getItem("infiniteScrollEnabled") == true || localStorage.getItem("infiniteScrollEnabled") == false)) {
    // init variable/set default variable for item
    localStorage.setItem("infiniteScrollEnabled", true);
}

Answer 1

The getItem method in the WebStorage specification, explicitly returns null if the item does not exist:

… If the given key does not exist in the list associated with the object then this method must return null. …

So, you can:

if (localStorage.getItem("infiniteScrollEnabled") === null) {
  //...
}

See this related question:

• Storing Objects in HTML5 localStorage