数组与对象的深拷贝

对象
//1
var newObject = JSON.parse(JSON.stringify(oldObject));

//2
function clone(obj) {
      if (obj === null || typeof(obj) !== 'object' || 'isActiveClone' in obj)
        return obj;

      if (obj instanceof Date)
        var temp = new obj.constructor(); //or new Date(obj);
      else
        var temp = obj.constructor();

      for (var key in obj) {
        if (Object.prototype.hasOwnProperty.call(obj, key)) {
          obj['isActiveClone'] = null;
          temp[key] = clone(obj[key]);
          delete obj['isActiveClone'];
        }
      }

      return temp;
    }

// Shallow copy
var newObject = jQuery.extend({}, oldObject);

// Deep copy
var newObject = jQuery.extend(true, {}, oldObject);

数组
let a=[1,2,3]
let b=a.slice();
let c=a.concat();//或者使用ES7  let c = [...a],转码后也是concat
console.log(a === b)//false
console.log(a === c)//false