英文:
TypeScript equivalent of Java method references
问题
我在TypeScript方面还是比较新手，但我对Java很了解。在Java中，每当需要满足函数式接口时，通常会使用lambda表达式（->）或方法引用（::）。
在这两种语言之间，lambda表达式似乎是等价的（如果我理解错了请纠正）。是否有办法利用方法引用？
当目标是实现以下内容时：
this.entryService.getEntries()
.subscribe(entries => this.listUpdateService.send(entries));
有没有办法使用函数引用？以下这种方式似乎是错误的，因为send不会在this.listUpdateService的作用域中执行。（顺便问一下，它在哪个作用域中执行？）
this.entryService.getEntries()
.subscribe(this.listUpdateService.send);
英文:
I'm sort of new to TypeScript, I know Java quite well though. There, whenever a functional interface needs to be satisfied, it's most commonly done using lambda expressions (->) or method references (::).
Lambda expressions seem to be equivalent between the two languages (correct me if I'm wrong). Is there a way to make use of method references?
When the goal is to achieve this:
this.entryService.getEntries()
.subscribe(entries => this.listUpdateService.send(entries));
Is there a way to use a function reference? The following way of doing it appears to be errorous, because send isn't executed in the scope of this.listUpdateService. (BTW, which scope is it executed in?)
this.entryService.getEntries()
.subscribe(this.listUpdateService.send);
答案1
得分: 2
你说得对，作用域不是 this.listUpdateService。
如果你想保持正确的作用域，通常会使用 bind。
this.entryService.getEntries()
.subscribe(this.listUpdateService.send.bind(this.listUpdateService));
英文:
You are right, the scope is not this.listUpdateService.
If you want to stick the correct scope, you normally use bind.
<!-- language: typescript -->
this.entryService.getEntries()
.subscribe(this.listUpdateService.send.bind(this.listUpdateService));
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