How to change a property on an object without mutating it?

Question

const a = {x: "Hi", y: "Test"}
const b = ???
// b = {x: "Bye", y: "Test"}
// a = {x: "Hi", y: "Test"}
         


        

Answer 1

Create a copy of the object and change the copy:

const b = Object.assign({}, a, {x: "Bye"})

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