克隆Node.js中的对象 [英] Cloning an Object in Node.js

问题描述

在node.js中克隆对象的最佳方法是什么

What is the best way to clone an object in node.js

例如。我想避免以下情况：

e.g. I want to avoid the situation where:

var obj1 = {x: 5, y:5};
var obj2 = obj1;
obj2.x = 6;
console.log(obj1.x); // logs 6

对象可能包含复杂类型作为属性，因此很简单（var x在obj1）不会解决。我是否需要自己编写一个递归克隆，或者是否有内置的东西我没有看到？

The object may well contain complex types as attributes, so a simple for(var x in obj1) wouldn't solve. Do I need to write a recursive clone myself or is there something built in that I'm not seeing?

推荐答案

可能性1

低档深拷贝：

Possibility 1

Low-frills deep copy:

var obj2 = JSON.parse(JSON.stringify(obj1));

可能性2（已弃用）

注意：此解决方案现已在 Node.js <的文档中标记为已弃用/ a>：

Possibility 2 (deprecated)

Attention: This solution is now marked as deprecated in the documentation of Node.js:

util._extend（）方法从不打算在内部Node.js模块之外使用。社区无论如何都找到并使用了它。

The util._extend() method was never intended to be used outside of internal Node.js modules. The community found and used it anyway.

它已被弃用，不应在新代码中使用。 JavaScript通过Object.assign（）提供非常相似的内置功能。<​​/ p>

It is deprecated and should not be used in new code. JavaScript comes with very similar built-in functionality through Object.assign().

原始答案：：

对于浅层副本，请使用Node的内置 util._extend（）函数。

For a shallow copy, use Node's built-in util._extend() function.

var extend = require('util')._extend;

var obj1 = {x: 5, y:5};
var obj2 = extend({}, obj1);
obj2.x = 6;
console.log(obj1.x); // still logs 5

Node的源代码 _extend 功能在这里： https://github.com/joyent/ node / blob / master / lib / util.js

Source code of Node's _extend function is in here: https://github.com/joyent/node/blob/master/lib/util.js

exports._extend = function(origin, add) {
  // Don't do anything if add isn't an object
  if (!add || typeof add !== 'object') return origin;

  var keys = Object.keys(add);
  var i = keys.length;
  while (i--) {
    origin[keys[i]] = add[keys[i]];
  }
  return origin;
};

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