How can a JS object be saved in localStorage?

The object needs to be converted into a JSON string.

// Creating an object
const userData = {
  name: 'John',
  age: 30,
  city: 'New York'
};

// Converting the object to a JSON string
const userDataString = JSON.stringify(userData);

// Saving the string in localStorage
localStorage.setItem('currentUser', userDataString);

// Example of retrieving and converting back to an object
const storedUserDataString = localStorage.getItem('currentUser');

if (storedUserDataString) {
  const storedUserData = JSON.parse(storedUserDataString);
  console.log(storedUserData.name); // Will output 'John'
}

localStorage can only store strings. JSON.stringify() converts a JavaScript object into a JSON-formatted string that can be saved. When retrieving data, JSON.parse() converts the JSON string back into a JavaScript object.