Deep clone an object in JavaScript

We can find many discussions and solutions about this issue.

In my case the one that worked is this code.

Below you’ll find a compressed version of the extend() function (with a fix):

function extend(){var r,t,n,o,e=arguments[0]||{},f=1,i=arguments.length,u=!1,y=function(r){if(null===r||"object"!=typeof r||r.nodeType||null!==r&&r===r.window)return!1;try{if(r.constructor&&!this.hasOwnProperty.call(r.constructor.prototype,"isPrototypeOf"))return!1}catch(t){return!1}return!0};for("boolean"==typeof e&&(u=e,e=arguments[f]||{},f++),"object"!=typeof e&&"function"!=typeof e&&(e={}),!1;i>f;f+=1)if(null!==(r=arguments[f]))for(t in r)e!==r[t]&&"undefined"==typeof e[t]&&(u&&r[t]&&(y(r[t])||(n=Array.isArray(r[t])))?(n?(n=!1,o=e[t]&&Array.isArray(e[t])?e[t]:[]):o=e[t]&&y(e[t])?e[t]:{},e[t]=extend(u,o,r[t])):void 0!==r[t]&&(e[t]=r[t]));return e}

And here an example:

var object_a = {
    value_1: 'a',
    value_2: true,
    value_3: 354,
    value_4: [
      'x',
      'y',
      'z'
    ],
    value_5: {
      I: 'I',
      II: 'II',
      III: 'III',
      IV: {
        a: 'A',
        b: 'B'
      },
      V: [
        'elm', {
          5: 'five'
        },
        ['my_array']
      ]
    },
    value_6: function() {
      return "pouet"
    },
    value_7: new Date(2017, 0, 1)
  };
var object_b = {};
// clone object_a into object_b
extend(true, object_b, object_a);
object_a.value_2 = false;
object_a.value_1 = "b";
console.log("A => ", object_a);
console.log("B => ", object_b);