ES6阵列理解是否不再有效？

问题描述

下面的ES6代码段无效。以前是有效的。我仍然可以在旧版本的Traceur中运行它，但最新的Babel和Traceur似乎不再像阵列中的for-loop那样喜欢。任何人都可以告诉我为什么它不再有效。

The ES6 code snippet below is invalid. It used to be valid. I can still run it in old versions of Traceur but the latest Babel and Traceur don't seem to like the for-loop in an array anymore. Can anyone tell me why it's no longer valid.

let people = [
    {
        "firstName": "Belinda",
        "phone": "1-607-194-5530",
        "email": "[e-mail]"
    },
    {
        "firstName": "Elizabeth",
        "phone": "1-155-446-1624",
        "email": "[e-mail]"
    }
]

let phones = [for({phone} of people) phone];
console.log(phones)

下面的代码片段是有效的ES6，所以我知道破坏里面一个for循环是OK

The snippet below is valid ES6 so I know the destructing inside a for-loop is OK

for(let {phone} of people) {
  console.log(phone)
}

推荐答案

数组解析是 。 没有提及理解，所以可能会被删除。通过ES的快速搜索讨论邮件列表档案在任何明确的方面都是空的。

Array comprehensions were removed in BabelJS version 6. The ES2015 Specification has no mention of comprehensions, so they were probably dropped. A quick search through the ES Discuss mailing list archives came up empty on anything definitive.

作为稍微更详细的替代方案，有（ES7中的功能）和 Array.prototype.map 。

As a slightly more verbose alternative there is Object.entries (a stage-3 feature in ES7) and Array.prototype.map.

let emails = people.map(({ email }) => email);

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