spread运算符

spread运算符

Last week I wrote 6 Great Uses of the Spread Operator, a post detailing how awesome the spread operator (...) is for working with arrays and other iterable objects.  As always my readers chimed in with a few other great uses and which you should check out in the comments.  And of course as soon as I publish the post I find another great use of the spread operator while I tinker with Babel and React:  merging multiple objects' properties into one object!

上周，我写了《 Spread运算符的6大用法》 ，详细介绍了Spread运算符( ... )对于处理数组和其他可迭代对象的效果。 像往常一样，我的读者还有其他一些很棒的用途，您应该在评论中查看。 当然，当我发布该帖子时，我在修补Babel和React时发现了散布运算符的另一种出色用法：将多个对象的属性合并到一个对象中！

JavaScript (The JavaScript)

Wrap any objects you'd like merged into one with braces ({}):

用大括号( {} )将要合并的所有对象包装起来：

const person = { name: 'David Walsh', gender: 'Male' }; const tools = { computer: 'Mac', editor: 'Atom' }; const summary = {...person, ...tools}; /* Object { "computer": "Mac", "editor": "Atom", "gender": "Male", "name": "David Walsh", } */

A new object is created containing all properties and values from the objects provided with the rest operator.  Also note that you can provide any number of objects to merge:

将创建一个新对象，其中包含rest运算符提供的对象中的所有属性和值。 还请注意，您可以提供任意数量的对象进行合并：

const person = { name: 'David Walsh', gender: 'Male' }; const tools = { computer: 'Mac', editor: 'Atom' }; const attributes = { handsomeness: 'Extreme', hair: 'Brown', eyes: 'Blue' }; const summary = {...person, ...tools, ...attributes}; /* Object { "computer": "Mac", "editor": "Atom", "eyes": "Blue", "gender": "Male", "hair": "Brown", "handsomeness": "Extreme", "name": "David Walsh", } */

In the case of a key collision, the right-most (last) object's value wins out:

如果发生键冲突，则最右边(最后一个)对象的值将获胜：

const person1 = { name: 'David Walsh', age: 33 }; const person2 = { name: 'David Walsh Jr.', role: 'kid' }; const merged = {...person1, ...person2} /* Object { "name": "David Walsh Jr.", "age": 33, "role": "kid", } */

I love how easy merging objects is using the spread operator.  You can use Object.assign to accomplish the same feat but the spread operator makes things a bit shorter if you don't mind a slightly less descriptive syntax!

我喜欢使用散布运算符轻松合并对象。 您可以使用Object.assign来完成相同的功能，但是如果您不介意描述性语法稍差一点，那么蔓延运算符会使事情变得更短！

Note:  This syntax is not yet support by all browsers but you can use Babel with the transform-object-rest-spread plugin to enable object merging with the spread operator.

注意：并非所有浏览器都支持此语法，但是您可以将Babel与transform-object-rest-spread插件一起使用，以启用对象与spread运算符的合并。

翻译自: https://davidwalsh.name/merge-objects

spread运算符

相关资源：jdk-8u281-windows-x64.exe