JSFiddle - React, Tailwind, and code Playground

JavaScript

function clone(object) {
  if (object instanceof Date) {
		var clone = new Date();
    
    clone.setFullYear(object.getFullYear());
    clone.setMonth(object.getMonth());
    clone.setDate(object.getDate());
    clone.setHours(object.getHours());
    clone.setMinutes(object.getMinutes());
    clone.setSeconds(object.getSeconds());
    clone.setMilliseconds(object.getMilliseconds());
  } else if (object instanceof RegExp) {
  	var clone = new RegExp;
  } else if (object instanceof Error) {
  	var clone = new Error();
  } else if (object instanceof Array) {
  	var clone = [];
  } else if (object instanceof Function) {
  	var clone = object.bind(clone);
  } else {
		var clone = {};
  }
  
  clone.length = object.length;
  clone.name = object.name;

  for (property in object) {
  	if (object.hasOwnProperty(property)) {
    	clone[property] = object[property];
    }
  }

  return clone;
}

var a = { x: 1, y: 2, z: [1, 2, 3] };
var b = clone(a);
b.x = 10;
console.log(a.x);

b.z.push(4);
console.log(a.z);

var c = new Date(2014, 1, 1);
var d = clone(c);
d.setFullYear(2015);
console.log(c.getFullYear());

console.log(c);
console.log(d);