ES6/2015 中的空安全属性访问(和条件赋值) [英] Null-safe property access (and conditional assignment) in ES6/2015

问题描述

在 ES6 (ES2015/JavaScript.next/Harmony) 中是否有类似 的 null 安全的属性访问(null 传播/存在)操作符?.<例如 CoffeeScript 中的/strong> ?还是计划用于 ES7?

Is there a null-safe property access (null propagation / existence) operator in ES6 (ES2015/JavaScript.next/Harmony) like ?. in CoffeeScript for example? Or is it planned for ES7?

var aThing = getSomething()
...
aThing = possiblyNull?.thing

大致如下:

if (possiblyNull != null) aThing = possiblyNull.thing

理想情况下，如果 possivelyNull 是 nullundefined)分配给 aThing>

Ideally the solution should not assign (even undefined) to aThing if possiblyNull is null

推荐答案

更新 (2020-01-31):似乎人们还在发现这个，这是当前的故事:

Update (2020-01-31): Seems people are still finding this, here's the current story:

• 可选链规范(第 4 阶段):https://github.com/tc39/proposal-可选链
• babel-preset-env:这可能就是你想要的 https://babeljs.io/docs/en/babel-preset-env
• Babel v7 插件:https://babeljs.io/docs/en/babel-plugin-proposal-optional-chaining

更新 (2017-08-01):如果你想使用官方插件，你可以尝试使用新转换的 Babel 7 的 alpha 版本.您的里程可能会有所不同

Update (2017-08-01): If you want to use an official plugin, you can try the alpha build of Babel 7 with the new transform. Your mileage may vary

https://www.npmjs.com/package/babel-插件转换可选链

原文:

目前处于第 1 阶段的功能:可选链.

A feature that accomplishes that is currently in stage 1: Optional Chaining.

https://github.com/tc39/proposal-optional-chaining

如果你今天想使用它，有一个 Babel 插件可以实现这一点.

If you want to use it today, there is a Babel plugin that accomplishes that.

https://github.com/davidyaha/ecmascript-optionals-proposal

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