怎样拷贝对象

方法一: 

function copyObject(orig) {
  var copy = Object.create(Object.getPrototypeOf(orig));
  copyOwnPropertiesFrom(copy, orig);
  return copy;
}

function copyOwnPropertiesFrom(target, source) {
  Object
    .getOwnPropertyNames(source)
    .forEach(function (propKey) {
      var desc = Object.getOwnPropertyDescriptor(source, propKey);
      Object.defineProperty(target, propKey, desc);
    });
  return target;
}

方法二: 

function copyObject(orig) {
  return Object.create(
    Object.getPrototypeOf(orig),
    Object.getOwnPropertyDescriptors(orig)
  );
}