解构嵌套对象：如何获取父级及其子级值？ [英] Destructuring nested objects: How to get parent and it's children values?

问题描述

在下面的函数中，我得到textarea对象，其属性为 current 。

In the below function, I get the textarea object with the property current .

这里，嵌套解构适用于开始和结束变量。但当前变量不起作用。

Here, nested destructuring works with Start and End variables. But current variable doesn't work.

function someFunction({ current: { selectionStart: Start, selectionEnd: End } }, AppStateSetter) {

    // do something with current, Start, and End
}

推荐答案

第一次解构仅创建开始和结束变量。如果你想创建当前作为变量，那么你需要再次声明它。

The first destructuring creates only Start and End variables. If you want to create current as a variable, then you need to declare it again.

function ({ current: { selectionStart: Start, selectionEnd: End }, current }, AppStateSetter) {

// do something with current , Start , and End

}

你可以在Babel编译器上测试它：

此代码：

const object = {
  current: {
    selectionStart: "prop 1",
    selectionEnd: "prop2"
  }
}

const { current: { selectionStart: Start, selectionEnd: End } } = object;

获取trasnpiled为：

Gets trasnpiled to:

var object = {
  current: {
    selectionStart: "prop 1",
    selectionEnd: "prop2"
  }
};

var _object$current = object.current,
    Start = _object$current.selectionStart,
    End = _object$current.selectionEnd;

如您所见，当前变量是没有创建。

As you can see, current variable is not created.

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