How to remove a property from a JavaScript object? (delete, spread and other methods)

Hello everyone! I just started learning JavaScript and encountered a problem. I have an object that contains user data: ```javascript const user = { name: 'Alexey', age: 30, email: 'alex@example.com', password: 'secret123', role: 'admin' }; ``` I need to remove the `password` property from this object before sending the data to the client (to avoid exposing the password). I tried assigning `undefined`: ```javascript user.password = undefined; ``` But this does not remove the property — it just becomes `undefined`. When serializing to JSON (JSON.stringify) it disappears, but the key remains in the object itself. And if I iterate over the object with `for...in`, `password` still shows up. I've heard about the `delete` operator, but I'm confused because some people say it's slow and should be avoided. Also, I read that `delete` doesn't work on properties inherited from the prototype. Are there other ways to remove a property? For example, using the spread operator to create a new object without the property? What is the best practice in modern JavaScript?