扩展操作符与Object.assign [英] Spread operator vs Object.assign

问题描述

假设我有一个选项变量，我想设置一些默认值。

这两个选项的优点/缺点是什么？

使用扩展运算符

  options = {... optionsDefault，... options }; 
  

或使用Object.assign

  options = Object.assign（{}，optionsDefault，options）; 
  

这是提交，这让我很奇怪。

解决方案

这不一定是详尽无遗的。

传播语法

  options = {... optionsDefault，... options}; 
  

优点：

• 如果在没有本机支持的环境中执行代码编写，您可能只需编译此语法（而不是使用polyfill）。 （以Babel为例）




• 较少详细

缺点：

• A 提案，不规范。 （请考虑你现在写什么，并且没有标准化）。




• 文字，而不是动态。

---

Object.assign（）

  options = Object.assign（{}，optionsDefault，options）; 
  

优点：

• 标准化。




• 动态。例如：

    var sources = [{a：A}，{b：B }，{c：C}]; 
   options = Object.assign.apply（Object，[{}]。concat（sources））; 
    




• 更详细。

缺点：

• 如果在没有本地支持的环境中执行的创作代码，则需要进行polyfill

---

这是让我想知道的提交

这与您所要求的不直接相关。该代码没有使用 Object.assign（），它使用的是用户代码（ object-assign ）一样的东西。他们似乎正在使用Babel编译代码（并将其与Webpack捆绑在一起），这正是我所说的：您可以编译的语法。他们显然希望不得不将 object-assign 作为依赖关系，进入他们的构建。

Let's say I have an options variable and I want to set some default value.

What's is the benefit / drawback of these two alternatives?

Use the spread operator

options = {...optionsDefault, ...options};

Or use Object.assign

options = Object.assign({}, optionsDefault, options);

This is the commit that made me wonder.

解决方案

This isn't necessarily exhaustive.

Spread syntax

options = {...optionsDefault, ...options};

Advantages:

• If authoring code for execution in environments without native support, you may be able to just compile this syntax (as opposed to using a polyfill). (With Babel, for example.)

• Less verbose.

Disadvantages:

• A proposal, not standardized. (Consider what you'd do if you write it now and it doesn't get standardized.)

• Literal, not dynamic.

---

Object.assign()

options = Object.assign({}, optionsDefault, options);

Advantages:

• Standardized.

• Dynamic. Example:

  var sources = [{a: "A"}, {b: "B"}, {c: "C"}];
  options = Object.assign.apply(Object, [{}].concat(sources));
  

• More verbose.

Disadvantages:

• If authoring code for execution in environments without native support you need to polyfill.

---

This is the commit that made me wonder.

That's not directly related to what you're asking. That code wasn't using Object.assign(), it was using user code (object-assign) that does the same thing. They appear to be compiling that code with Babel (and bundling it with Webpack), which is what I was talking about: the syntax you can just compile. They apparently preferred that to having to include object-assign as a dependency that would go into their build.

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