"use strict"; // replaceAll if (String.prototype.replaceAll === undefined) { String.prototype.replaceAll = function (str, newStr) { if (Object.prototype.toString.call(str).toLowerCase() === "[object regexp]") return this.replace(str, newStr); return this.replace(new RegExp(str, "g"), newStr); }; } // flat if (Array.prototype.flat === undefined) { Array.prototype.flat = function () { return this.reduce((acc, val) => (Array.isArray(val) ? acc.concat(val.flat()) : acc.concat(val)), []); }; }