Deep copy of three ways

• Method JSON
  var obj2 = JSON.parse (JSON.stringify (obj1 )) // deep copy

• Recursively (to itself) method for determining the type attribute of the first layer, the properties of the multilayer copy target
  var OBJ1 = {
  name: 'ZS',
  Age: 18 is,
  Dog: {
  name: 'Golden',
  Age: 2
  },
  Friends : [ 'WW', 'Lil']
  }
  var obj2 = {};
  function the deepCopy (O1, O2) {
  for (var K in O1) {
  // if the property in the first layer is an array of complex type
  if (o1 [ K] the instanceof the array) {
  o2 [k] = []; // if o1 [k] is an array, then to the o2 [k] is also prepared a copied content storage array
  deepCopy (o1 [k], o2 [k ]);
  }
  // if the properties in the first layer is a complex type object
  the else IF (O1 [K] the instanceof Object) {
  O2 [K] = {};
  the deepCopy (O1 [K], O2 [K]);
  } {the else
  O2 [K] O1 = [K];
  }
  }
  }
  the deepCopy (OBJ1, obj2);
  obj1.name = 'Lisi';
  obj1.dog.name = 'rhubarb';
  the console.log (OBJ1);
  the console.log (obj2);

• Object.created ();
  // the Object.create () specific use
  var obj = {name: 'Lisi'};
  var = newobj the Object.create (obj);
  // newobj prototype ( proto ) pointing obj, comprising the obj properties and methods