check localstorage value exists code example

Example 1: check if localstorage key exists

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

Example 2: check if item exists in localstorage javascript

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

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