JSFiddle - React, Tailwind, and code Playground
JavaScript
// Object.defineProperty in javascript
/* writable:false is used to set read only property */
var alert = function (str) {
var st = document.createTextNode(str);
var p = document.createElement('p');
p.appendChild(st);
document.querySelector('body').appendChild(p);
}
var o = {};
Object.defineProperty(o, "test", {
writable: false,
value: 123
});
alert(o.test)
o.test = 200;
alert(o.test)