销毁array.map()中的对象属性并将对象保留为参数 [英] Destruct object properties in array.map() and keep object as parameter

问题描述

是否可以破坏对象的属性，同时将对象保留为array.map()函数中的参数?

Is it possible to destruct the properties of an object while keeping the object as a parameter inside an array.map() function?

基于此问题我尝试了以下操作，但失败了(解析错误)

Based on this question I tried the following but failed (parsing error)

  this.state.files.map(((file, {param1, param2} = file), i) => (
    <div key={i}>
      <p>{param1}</p>
      <button onClick={this.editFile(file)} />
    </div>
  )

推荐答案

实现此目标的一种方法是使用

One way to achieve this would be to use the default parameters syntax, like so:

const test = (input, { a, b } = input) => [ a, b ]
console.log(test({ a: 1, b: 2 })) // [ 1, 2 ]

没有第二个参数传递给上面的函数，因此第二个参数默认为第一个参数，然后将其销毁.

No second parameter is passed to the function above, so the second parameter defaults to the first parameter, then it is destructed.

该参数只能在声明后使用，因此将无法使用:

The parameter can only be used after it has been declared, so this won't work:

const test = ({ a, b } = input, input) => [ a, b ]
console.log(test(undefined, { a: 1, b: 2 }))
// Uncaught ReferenceError: input is not defined at test

这也仅在没有传递参数的情况下有效，因此，在将回调传递给Array#map的情况下，必须声明所有传递的参数，以便可以声明默认参数.

This can also only work if no parameter is passed, so in the case of a callback being passed to Array#map, you must declare all of the parameters being passed so that you can declare the default parameter.

以您的示例为例:

this.state.files.map((file, i, files, { param1, param2 } = file) => (
  <div key={i}>
    <p>{param1}</p>
    <button onClick={this.editFile(file)} />
  </div>
))

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