Whenever you have a reference type in which the equality (the same object in memory) doesn't make sense (think of String.Equals). How can I override that 2311 value if it already exists without mutating the state. The toJSON () method returns a date object as a string, formatted as a JSON date. The expression to extract the name property value using object destructuring is the following: const { name } = user; console.log (name); // Output, Alex As you see, on the left side of the expression, we pick the object property key ( name in this case) and place it inside the {}.