I'm new to react, i'm trying to do something that should be very simple: use the spread operator (...) to create a copy of an object OMITTING ONE PROPERTY...

I've tried to follow some posts here, when i test then in javascript emulator they work, but they dont work in my real case

const obj = { a : 'a', b : 'b', c : 'c'};
const [formData, setFormData] = useState({a,...obj});

console.log(formData);

I get the error

Uncaught ReferenceError: a is not defined