JSFiddle - React, Tailwind, and code Playground

JavaScript

var obj = {};

Object.defineProperty(obj, "foo", {

    configurable: true,
    value: "bar",
});


Object.defineProperty(obj, "foo", {
    value: "boobar",
});


Object.defineProperty(obj, "foo", {
    writable: true 
});

Object.defineProperty(obj, "foo", {
    value: "boobar",
});
console.log(obj.foo)


// Uncaught TypeError: Cannot redefine property: foo