JSFiddle - React, Tailwind, and code Playground

by tonytlwu

JavaScript

var ClassName = function () {
  this.run();
};

ClassName.prototype.flag = false;

ClassName.prototype.run = function () {
  console.log(1, this.flag);
  ClassName.prototype.flag = true;
  console.log(2, this.flag);
};

new ClassName();
new ClassName();