If missing, the expectation is that it's return `undefined` just like how `a.foo` returns `undefined` if `a` has no property `"foo"`. It's just shorthand for `x => x.foo` and similar.
On Thu, Jun 27, 2019 at 20:30 guest271314 <[email protected]> wrote: > How can the Selector/Select Expression be used with > `Array.prototype.find()`? What happens when the property is not defined? > > For example using the same code for more than one browser > > ``` > const stream = [canvasStream, videoTrack].find(({requestFrame: _}) => _); > ``` > > the property `requestFrame` is either defined or not defined at > ```canvasStream``` or ```videoTrack``` depending on the implementation. > Although the assigned variable can be reduced to 1 character at > destructuring assignment, there is still the redundancy of writing ```_``` > again on the right side of ```=>```. > > If the property is not found, is the result ```undefined```? > > What is the least amount characters necessary using Selector/Select > Expression with ```find()```? > > ``` > const stream = [canvasStream, videoTrack].find(=.requestFrame); > ``` > > ? > > On Thu, Jun 27, 2019 at 8:48 PM Bob Myers <[email protected]> wrote: > >> Not exactly, since the optional chaining operator is `?.` with no space >> in between. >> >> On Thu, Jun 27, 2019 at 1:37 PM Simon Farrugia <[email protected]> >> wrote: >> >>> Also, without a leading token, a selector expr with the optional >>> chaining operator inside a ternary operator would be ambiguous. >>> >>> ``` >>> >>> const contactSelector = true ? .contacts.email : .contacts.phone; >>> >>> ``` >>> >>> >>> _______________________________________________ >> es-discuss mailing list >> [email protected] >> https://mail.mozilla.org/listinfo/es-discuss >> > _______________________________________________ > es-discuss mailing list > [email protected] > https://mail.mozilla.org/listinfo/es-discuss > -- ----- Isiah Meadows [email protected] www.isiahmeadows.com
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